Achilles tendinitis (also spelled tendonitis) is inflammation of the tissue that connects your calf muscle to your heel (Achilles tendon). Inflammation is your body’s response to injury or disease. Achilles tendinitis is a common condition in runners. When you run, your calf muscles help raise you up on your toes. Over time, this repetitive motion, combined with not giving your …

Ulcerative colitis (UC) is a lifelong condition that causes inflammation and ulcers inside your colon (large intestine). UC is one of the most common types of inflammatory bowel disease (IBD), alongside Crohn’s disease. UC often causes bloody diarrhea and abdominal cramping. It may make you have to poop more. Most people with UC experience periods when they experience symptoms (flare-ups), followed by longer …

Waldenstrom macroglobulinemia is a rare slow-growing cancer that affects your blood cells. It’s a type of non-Hodgkin’s lymphoma. (Healthcare providers may refer to this condition by the initials WM or the name lymphoplasmacytic lymphoma). WM happens when genetic mutations change certain blood cells, setting up a chain reaction of medical conditions that may be life-threatening. Providers can’t cure this condition, but they do …

Dry skin is skin that doesn’t have enough moisture in it to keep it feeling soft. The medical term for dry skin is xeroderma (pronounced “ze-ROW-derm-ah”). Xerosis (pronounced “ze-ROW-sis”) is severely dry skin. Dry skin feels like rough patches of your skin that can flake or look scaly. If your skin is dry, it may or may not be itchy (pruritis). Severe dry …

A Zenker’s diverticulum is an issue that affects your throat (pharynx). It’s a pouch that forms at the bottom of your throat where your throat connects to your esophagus. The pouch traps food, making it hard for you to swallow. Zenker’s diverticulum typically affects people aged 70 to 90. You may have this condition for years before you develop noticeable symptoms, …

A vaginal yeast infection is a type of fungal infection. Your body contains a kind of yeast called candida, which causes vaginal yeast infections. Yeast is a type of fungus, and candida is a specific type of yeast. When this yeast is in balance within your body, there are no problems. But when the yeast is out of balance, it rapidly …

Jet lag, also called jet lag disorder, is a temporary sleep problem that can affect anyone who quickly travels across several time zones. Your body has its own internal clock, called circadian rhythms. They signal to your body when to stay awake and when to sleep. Jet lag occurs because your body’s internal clock is synced to your original time …

Jellyfish are sea creatures that live in all of the world’s oceans. They have soft, bell-shaped bodies with lengthy, finger-like structures called tentacles. Jellyfish have stinging cells called nematocysts inside of their tentacles. A single tentacle may contain thousands of nematocysts. Nematocysts contain a poisonous substance (venom) that helps jellyfish protect themselves. The venom also helps them capture food by …

Swine flu (H1N1) is an infection that a type of flu (influenza) virus causes. It’s called swine flu because it’s similar to a flu virus that affects pigs (swine). The virus leads to a lung (respiratory) disease in pigs. Swine flu (H1N1) is a respiratory infection in humans. Are swine flu (H1N1) and Spanish flu the same thing? In 1918, a flu …

Galactorrhea (guh-lack-toe-REE-uh) happens when your breasts unexpectedly produce milk or a milk-like discharge. This nipple discharge may leak from your breast on its own or when touched. It’s not related to milk production in breastfeeding (chestfeeding) or pregnancy. Galactorrhea sometimes indicates an underlying health condition, but is most often caused by too much prolactin. Prolactin is a hormone that triggers milk production. It’s made by your pituitary …