Use the A-Z list to browse more than 6,000 health-related topics in our library. Clicking on a term opens the definition and, in most cases, links to more information.
"H Pylori" is more commonly referred to as "Helicobacter Pylori" in the medical community. Helicobacter Pylori
Also Known As: "Campylobacter Pylori"
Bacteria often found in the stomach. While they frequently cause no problems, they may damage stomach and duodenal tissue, causing ulcers. More Information on Helicobacter Pylori: Gastritis & Ulcer
"HACCP" is more commonly referred to as "Critical Control Points" in the medical community. Critical Control Points
Also Known As: "CCP, Hazard Analysis and Critical Control Points"
A process of steps and procedures related to food production which, if properly followed, will reduce or eliminate a food safety hazard (e.g., food borne illness).
"Haemophilus Ducreyi Infection" is more commonly referred to as "Chancroid" in the medical community. Chancroid
A sexually transmitted disease caused by the bacterium Hemophilus ducreyi that results in painful sores on the genitalia. Left untreated, it may make transmission of HIV easier. More Information on Chancroid: STD & Genital Infections
"Haemophilus Influenzae" is more commonly referred to as "Hib Infection" in the medical community. Hib Infection
Also Known As: "Haemophilus Influenzae Serotype B Infection, Hib Disease, Haemophilus Influenzae B, Haemophilus Influenzae Type B"
Infection with the Haemophilus influenzae type b (Hib) bacteria that infects the lining of the brain and causes meningitis. It was once the chief cause of meningitis. However, vaccination has sharply reduced such infections in the United States. More Information on Hib Infection: Brain Related Infections
"Haemophilus Influenzae B" is more commonly referred to as "Hib Infection" in the medical community. Hib Infection
Also Known As: "Hib Disease, Haemophilus Influenzae Type B, Haemophilus Influenzae, Haemophilus Influenzae Serotype B Infection"
Infection with the Haemophilus influenzae type b (Hib) bacteria that infects the lining of the brain and causes meningitis. It was once the chief cause of meningitis. However, vaccination has sharply reduced such infections in the United States. More Information on Hib Infection: Brain Related Infections
"Haemophilus Influenzae Serotype B Infection" is more commonly referred to as "Hib Infection" in the medical community. Hib Infection
Also Known As: "Hib Disease, Haemophilus Influenzae B, Haemophilus Influenzae Type B, Haemophilus Influenzae"
Infection with the Haemophilus influenzae type b (Hib) bacteria that infects the lining of the brain and causes meningitis. It was once the chief cause of meningitis. However, vaccination has sharply reduced such infections in the United States. More Information on Hib Infection: Brain Related Infections
"Haemophilus Influenzae Type B" is more commonly referred to as "Hib Infection" in the medical community. Hib Infection
Also Known As: "Hib Disease, Haemophilus Influenzae, Haemophilus Influenzae Serotype B Infection, Haemophilus Influenzae B"
Infection with the Haemophilus influenzae type b (Hib) bacteria that infects the lining of the brain and causes meningitis. It was once the chief cause of meningitis. However, vaccination has sharply reduced such infections in the United States. More Information on Hib Infection: Brain Related Infections
A rare hereditary blistering skin disease that often affects the skin folds, including the armpits, groin, neck, under the breasts and between the buttocks. Heat, sweating and friction often exacerbate the disease. More Information on Haily Haily Disease: Perspiration & Chafing
"Hair Loss" is more commonly referred to as "Alopecia" in the medical community. Alopecia
A condition in which the hair falls out, leading to baldness. It may result from chemotherapy or radiation therapy used in the treatment of cancer. In most cases, hair regrowth occurs once treatment is ended. More Information on Alopecia: Cancer Basics
Hair loss is defined as losing enough hair that a person has visibly thin or balding patches. It can occur for many reasons, including hormones, genetics, illness, poor nutrition, stress and reaction to medications. More Information on Hair Loss Basics: Alopecia (Hair Loss)
Also Known As: "Hair Restoration Surgery, Hair Loss Treatments, Hair Restoration Treatments"
Treatment to restore the hairline of a person who has experienced hair loss. Surgical techniques include hair transplants, scalp reductions, and skin lifts and grafts. Medications are also an option for some patients. More Information on Hair Loss Surgery: Alopecia (Hair Loss)
Also Known As: "Hair Restoration Treatments, Hair Loss Surgery, Hair Restoration Surgery"
Treatment to restore the hairline of a person who has experienced hair loss. Surgical techniques include hair transplants, scalp reductions, and skin lifts and grafts. Medications are also an option for some patients. More Information on Hair Loss Treatments: Alopecia (Hair Loss)
"Hair Pulling Disorder" is more commonly referred to as "Trichotillomania" in the medical community. Trichotillomania
Also Known As: "Compulsive Hair Pulling"
Hair loss from compulsive pulling and/or twisting of the hair, which may be lost in round patches or across the scalp. Areas such as eyebrows, eyelashes or body hair may be plucked. The cause of this compulsive behavior is unknown. More Information on Trichotillomania: Impulse Control Disorders
Also Known As: "Hair Loss Treatments, Hair Restoration Treatments, Hair Loss Surgery, Hair Restoration Surgery"
Treatment to restore the hairline of a person who has experienced hair loss. Surgical techniques include hair transplants, scalp reductions, and skin lifts and grafts. Medications are also an option for some patients. More Information on Hair Restoration: Alopecia (Hair Loss)
Also Known As: "Hair Loss Treatments, Hair Restoration Treatments, Hair Loss Surgery"
Treatment to restore the hairline of a person who has experienced hair loss. Surgical techniques include hair transplants, scalp reductions, and skin lifts and grafts. Medications are also an option for some patients. More Information on Hair Restoration Surgery: Alopecia (Hair Loss)
Also Known As: "Hair Loss Surgery, Hair Restoration Surgery, Hair Loss Treatments"
Treatment to restore the hairline of a person who has experienced hair loss. Surgical techniques include hair transplants, scalp reductions, and skin lifts and grafts. Medications are also an option for some patients. More Information on Hair Restoration Treatments: Alopecia (Hair Loss)
Hair loss is defined as losing enough hair that a person has visibly thin or balding patches. It can occur for many reasons, including hormones, genetics, illness, poor nutrition, stress and reaction to medications. More Information on Hair Thinning: Alopecia (Hair Loss)
Cancer and cancer treatments can causes changes to the hair, skin and nails. Patients should be aware of these issues and the steps they can take to minimize their impact on quality of life. More Information on Hair, Skin, Nail Issues & Cancer: Cancer Basics
A rare form of chronic leukemia that involves abnormally shaped B lymphocytes (known as "hairy cells"). It is four times more common in men than women and is potentially fatal. Treatment usually involves chemotherapy. More Information on Hairy Cell Leukemia: Leukemia & Bone Cancer
"Hairy Cells" is more commonly referred to as "B Cells" in the medical community. B Cells
Also Known As: "B Lymphocytes"
A type of white blood cell (WBC) that is produced in the bone marrow or spleen. It is part of the immune system. Mature B cells (plasma cells) produce antibodies to fight infection and disease. Tumors can develop within them (e.g., B cell lymphoma). More Information on B Cells: Leukemia & Bone Cancer
Also Known As: "Dark Tongue, Lingua Villosa, Black Hairy Tongue, Lingua Villosa Nigra, Lingua Nigra"
A benign condition in which the tongue appears to be covered in hair (usually appearing black, but may also be other colors). These "hairs" are actually overgrowth of normal fingerlike projections on the tongue that have trapped bacteria. More Information on Hairy Tongue: Mouth & Tongue Disorders
An unpleasant odor in the mouth that may be caused by tooth decay, smoking, gum disease, digestive problems or certain other diseases. More Information on Halitosis: Mouth & Tongue Disorders
"Hall Syndrome II" is more commonly referred to as "Pallister Hall Syndrome" in the medical community. Pallister Hall Syndrome
Also Known As: "MISHAP Syndrome, Congenital Hypothalamic Hamartoblastoma, Hypothalamic Hamartoblastoma Syndrome, RALPH Syndrome, 4H Syndrome, Hamartopolydactyly Syndrome"
A multiple congenital anomaly/mental retardation (MCA/MR) syndrome that may include one or more congenital heart defects such as patent ductus arteriosus, ventricular septal defect, coarctation of the aorta, and mitral or aortic valve defects. More Information on Pallister Hall Syndrome: Pediatric Heart
"Hallervorden Spatz Disease" is more commonly referred to as "Neurodegeneration with Brain Iron Accumulation" in the medical community. Neurodegeneration with Brain Iron Accumulation
Also Known As: "Pantothenate Kinase Associated Neurodegeneration"
An inherited, neurological movement disorder marked by progressive degeneration of the nervous system. Periods of relative stability may alternate with periods of rapid deterioration. More Information on Neurodegeneration with Brain Iron Accumulation: Movement Disorders
Drugs that affect perception, thought or feeling, typically resulting in hallucinations. These include LSD, mescaline, MDMA, PCP and psilocybin, among others. More Information on Hallucinogens: Alcohol & Substance Abuse
A device that encircles and is affixed to the head of a patient to immobilize the cervical spine (portion of the spine within the neck). More Information on Halo Crown: Back, Neck & Shoulder Pain
Moles surrounded by white rings, or halos. Usually found in children or young adults, they are the result of a circulating antibody and special white cells (T cells) that attack the pigment cells in the mole and some surrounding tissue. More Information on Halo Moles: Skin Discoloration
A device that encircles and is affixed to the head of a patient to immobilize the cervical spine (portion of the spine within the neck). More Information on Halo Ring: Back, Neck & Shoulder Pain
A device that encircles and is affixed to the head of a patient to immobilize the cervical spine (portion of the spine within the neck). More Information on Halo Vest: Back, Neck & Shoulder Pain
An antipsychotic medication used in the treatment of schizophrenia and other psychotic disorders, as well as Tourette's syndrome. More Information on Haloperidol: Psychiatric Medications
"Haloperidol" is more commonly referred to as "Thioridazine" in the medical community. Thioridazine
Also Known As: "Molindone, Pimozide, Loxapine"
A type of antipsychotic, medication used to treat schizophrenia and symptoms such as hallucinations, delusions and hostility. More Information on Thioridazine: Psychiatric Medications
"Halsted Radical Mastectomy" is more commonly referred to as "Radical Mastectomy" in the medical community. Radical Mastectomy
A surgery that involves removal of the breast, skin, nipple and areola, as well as the lymph nodes under the arm and the chest muscles on the same side of the body. Formerly the standard surgical treatment for breast cancer, it is rarely used today. More Information on Radical Mastectomy: Breast Cancer
A tumor that is made of cells and tissue normally found in the area of the body where the tumor appears. It is usually benign (noncancerous) and stops growing once cells reach maturity. More Information on Hamartoma: Cancer Basics
"Hamartopolydactyly Syndrome" is more commonly referred to as "Pallister Hall Syndrome" in the medical community. Pallister Hall Syndrome
Also Known As: "MISHAP Syndrome, Congenital Hypothalamic Hamartoblastoma, Hypothalamic Hamartoblastoma Syndrome, RALPH Syndrome, 4H Syndrome, Hall Syndrome II"
A multiple congenital anomaly/mental retardation (MCA/MR) syndrome that may include one or more congenital heart defects such as patent ductus arteriosus, ventricular septal defect, coarctation of the aorta, and mitral or aortic valve defects. More Information on Pallister Hall Syndrome: Pediatric Heart
A claw-like bending of the toe joints. It can lead to foot ulcer or serious infections. People with diabetes are at higher risk for foot problems, which can be avoided by wearing shoes that fit properly. More Information on Hammertoe: Arm & Leg Pain
A group of three muscles in the back of the thigh that bends the knee and moves the leg backward from the trunk of the body. More Information on Hamstring: Arm & Leg Pain
"Hamstring Muscle Sprain" is more commonly referred to as "Pulled Hamstring" in the medical community. Pulled Hamstring
Also Known As: "Hamstring Muscle Strain"
A strain or tear of the muscles or tendons at the back of the knee. Mild injuries may feel like a tightening while more severe injuries result in sharp pain or temporary inability to walk. Treatments may include rest and rehabilitation or surgery. More Information on Pulled Hamstring: Arm & Leg Pain
"Hamstring Muscle Strain" is more commonly referred to as "Pulled Hamstring" in the medical community. Pulled Hamstring
Also Known As: "Hamstring Muscle Sprain"
A strain or tear of the muscles or tendons at the back of the knee. Mild injuries may feel like a tightening while more severe injuries result in sharp pain or temporary inability to walk. Treatments may include rest and rehabilitation or surgery. More Information on Pulled Hamstring: Arm & Leg Pain
Also Known As: "Vibratory Syndrome, HAVS, Vibration Syndrome"
Disorder caused by prolonged exposure to vibration, specifically to the hands and forearms while using vibrating tools. Symptoms include numbness, tingling, loss of sensitivity, pain, muscle weakness and fatigue in the arms, shoulders and fingers. More Information on Hand Arm Vibration Syndrome: Arm & Leg Pain
A grouping of symptoms that occur in the hands and feet that may occur as a result of some cancer treatments. This includes pain, swelling, burning or tingling, numbness or redness. More Information on Hand Foot Syndrome: Cancer Basics
Also Known As: "HFMD, Vesicular Stomatitis with Exanthem"
Contagious infection caused by the coxsackievirus marked by small blistering oral lesions that progress to the hands, feet and other areas. Usually found in children, lesions due to this disease heal in about a week. More Information on Hand, Foot & Mouth Disease: Skin Related Infections
The effects of consuming an excess amount of alcohol usually followed by unbearable symptoms (e.g., headache, fatigue, muscle aches, nausea, stomach pain, heightened sensitivity to light and sound, dizziness, depression, anxiety, irritability). More Information on Hangover: Alcohol & Substance Abuse
"Hansen Disease" is more commonly referred to as "Leprosy" in the medical community. Leprosy
Also Known As: "Lepra, Hansenosis, Hanseniasis"
A disease caused by a bacterial infection that occurs in tropical and sub-tropical regions. If untreated it is characterized by skin lesions, and may also involve the loss of sensation, muscle weakness and paralysis. More Information on Leprosy: Skin Related Infections
"Hanseniasis" is more commonly referred to as "Leprosy" in the medical community. Leprosy
Also Known As: "Hansen Disease, Lepra, Hansenosis"
A disease caused by a bacterial infection that occurs in tropical and sub-tropical regions. If untreated it is characterized by skin lesions, and may also involve the loss of sensation, muscle weakness and paralysis. More Information on Leprosy: Skin Related Infections
"Hansenosis" is more commonly referred to as "Leprosy" in the medical community. Leprosy
Also Known As: "Lepra, Hanseniasis, Hansen Disease"
A disease caused by a bacterial infection that occurs in tropical and sub-tropical regions. If untreated it is characterized by skin lesions, and may also involve the loss of sensation, muscle weakness and paralysis. More Information on Leprosy: Skin Related Infections
Also Known As: "New York 1 Virus Infection, HPS, Sin Nombre Virus Infection"
A rare but deadly disease transmitted by infected rodents through urine, droppings or saliva. Humans contract the disease by breathing in the aerosolized virus. First recognized in 1993, it has been identified throughout the United States. More Information on Hantavirus: Pneumonia & Lung Infection
Also Known As: "New York 1 Virus Infection, Hantavirus, HPS, Sin Nombre Virus Infection"
A rare but deadly disease transmitted by infected rodents through urine, droppings or saliva. Humans contract the disease by breathing in the aerosolized virus. First recognized in 1993, it has been identified throughout the United States. More Information on Hantavirus Pulmonary Syndrome: Pneumonia & Lung Infection
"Hardening of the Arteries" is more commonly referred to as "Atherosclerosis" in the medical community. Atherosclerosis
Also Known As: "Blockage of the Arteries, Narrowing of the Arteries"
A disease in which the arteries harden and become narrowed due to the gradual build up of plaque on their inner walls. More Information on Atherosclerosis: Vascular Disease
Also Known As: "Ichthyosis Fetalis, Keratosis Diffusa Fetalis, Ichthyosis Congenita, Harlequin Fetus"
A condition present from birth in which the baby has thick, armor-like scales instead of skin, divided by deep red fissures or cracks. While often fatal within days, improvements have been made in care and some children survive into adulthood. More Information on Harlequin Baby: Psoriasis & Autoimmune Skin
Also Known As: "Ichthyosis Fetalis, Keratosis Diffusa Fetalis, Harlequin Baby, Ichthyosis Congenita"
A condition present from birth in which the baby has thick, armor-like scales instead of skin, divided by deep red fissures or cracks. While often fatal within days, improvements have been made in care and some children survive into adulthood. More Information on Harlequin Fetus: Psoriasis & Autoimmune Skin
Also Known As: "Ichthyosis Fetalis, Keratosis Diffusa Fetalis, Harlequin Fetus, Harlequin Baby, Ichthyosis Congenita"
A condition present from birth in which the baby has thick, armor-like scales instead of skin, divided by deep red fissures or cracks. While often fatal within days, improvements have been made in care and some children survive into adulthood. More Information on Harlequin Ichthyosis: Psoriasis & Autoimmune Skin
A method of straightening and stabilizing the spine after spinal fusion in which a rod is attached to the spine to redistribute the stresses on the bones. It is used when curvature is greater than 60 degrees, and is a treatment for scoliosis. More Information on Harrington Rod Instrumentation: Back, Neck & Shoulder Pain
"Hashimoto Disease" is more commonly referred to as "Hypothyroidism" in the medical community. Hypothyroidism
Also Known As: "Underactive Thyroid"
A disorder in which the thyroid gland is not producing enough thyroid hormones to meet the body's needs. Most people with hypothyroidism will need to take synthetic thyroid hormones for life to relieve symptoms and avoid long-term consequences. More Information on Hypothyroidism: Thyroid & Parathyroid
Autoimmune disorder in which the body's immune system attacks the thyroid gland. This causes inflammation that often results in hypothyroidism. More Information on Hashimoto's Thyroiditis: Thyroid & Parathyroid
"HAV" is more commonly referred to as "Hepatitis A" in the medical community. Hepatitis A
Also Known As: "Hep A"
A liver infection caused by an RNA virus and transmitted by ingestion of infected food and water. It has a shorter incubation and generally milder symptoms than hepatitis B. More Information on Hepatitis A: Liver, Pancreas & Biliary
Also Known As: "Vibratory Syndrome, Vibration Syndrome"
Disorder caused by prolonged exposure to vibration, specifically to the hands and forearms while using vibrating tools. Symptoms include numbness, tingling, loss of sensitivity, pain, muscle weakness and fatigue in the arms, shoulders and fingers. More Information on HAVS: Arm & Leg Pain
"Hay Fever" is more commonly referred to as "Allergic Rhinitis" in the medical community. Allergic Rhinitis
Also Known As: "Seasonal Allergic Rhinitis, Sporadic Allergic Rhinitis, Perennial Allergic Rhinitis"
Inflammation of the mucous membrane that lines the nose due to an allergic reaction to pollen, dust or other airborne substances. Seasonal rhinitis (also called hay fever) is more common, but allergic rhinitis can also be perennial (year round). More Information on Allergic Rhinitis: Nose & Throat
"Hay Fever & Children" is more commonly referred to as "Allergic Rhinitis & Children" in the medical community. Allergic Rhinitis & Children
Young children are less likely to experience this inflammation of the nasal passages caused by allergies. As children grow, they are likely to be exposed to dust, pollens and other allergens that may eventually trigger allergic rhinitis. More Information on Allergic Rhinitis & Children: Pediatric Allergy & Asthma
"Hay Fever Conjunctivitis" is more commonly referred to as "Allergic Conjunctivitis" in the medical community. Allergic Conjunctivitis
Also Known As: "Seasonal Allergic Conjunctivitis, Allergic Rhinoconjunctivitis, Eye Allergy, Perennial Allergic Conjunctivitis"
Inflammation of the conjunctiva, the tissue lining the inside of the eyelid, caused by an allergic reaction. Can be seasonal (occurring at certain times of the year) or perennial (year-round). More Information on Allergic Conjunctivitis: Eye Conditions
"Hazard Analysis and Critical Control Points" is more commonly referred to as "Critical Control Points" in the medical community. Critical Control Points
Also Known As: "CCP, HACCP"
A process of steps and procedures related to food production which, if properly followed, will reduce or eliminate a food safety hazard (e.g., food borne illness).
Physically or mentally tormenting a subordinate. It often occurs through humiliation or the performance of dangerous tasks that must be accomplished to ensure membership in a group.
"Hb A1c" is more commonly referred to as "Glycohemoglobin Test" in the medical community. Glycohemoglobin Test
Also Known As: "Fasting Hemoglobin, GHb Test, Diabetic Control Index, Hemoglobin A1C Test, Glycosylated Hemoglobin Test, Total Fasting Hemoglobin Test, HbA1C Test"
A blood test that is used to monitor diabetes, a risk factor for heart disease. It measures the levels of hemoglobin in the blood that have been glycosylated, or connected to glucose. More Information on Glycohemoglobin Test: Diabetes & Endocrine Tests
"HbA1C Test" is more commonly referred to as "Glycohemoglobin Test" in the medical community. Glycohemoglobin Test
Also Known As: "Fasting Hemoglobin, GHb Test, Diabetic Control Index, Hemoglobin A1C Test, Glycosylated Hemoglobin Test, Total Fasting Hemoglobin Test, Hb A1c"
A blood test that is used to monitor diabetes, a risk factor for heart disease. It measures the levels of hemoglobin in the blood that have been glycosylated, or connected to glucose. More Information on Glycohemoglobin Test: Diabetes & Endocrine Tests
"HBV" is more commonly referred to as "Hepatitis B" in the medical community. Hepatitis B
Also Known As: "Hep B"
A liver infection caused by a DNA virus and transmitted by contaminated blood products, sexual contact or use of contaminated needles and instruments. It has a long incubation and may cause serious damage to the liver. More Information on Hepatitis B: Liver, Pancreas & Biliary
Also Known As: "High Carbohydrate High Fiber Diet"
An eating plan high in both carbohydrates and dietary fiber that some believe can help control diabetes. It developed after increases in diabetes rates were observed in non-Western cultures when people began eating more refined and processed foods. More Information on HCF Diet: Diabetes Diet & Fitness
A rare form of chronic leukemia that involves abnormally shaped B lymphocytes (known as "hairy cells"). It is four times more common in men than women and is potentially fatal. Treatment usually involves chemotherapy. More Information on HCL Leukemia: Leukemia & Bone Cancer
"HCV" is more commonly referred to as "Hepatitis C" in the medical community. Hepatitis C
Also Known As: "Chronic Hepatitis C, Hepatitis C Virus, Hep C"
A liver infection caused by an RNA virus and transmitted primarily by blood and blood products or sexual contact. Most cases of non-A, non-B hepatitis are of this type, and it is clinically indistinguishable from hepatitis B. More Information on Hepatitis C: Liver, Pancreas & Biliary
