Barrett esophagus occurs when the normal cells that line your food pipe (esophagus) turn into cells not usually found in your body. The new cells take over because the lining of the esophagus has been damaged. The new, abnormal cells are called specialized columnar cells or intestinal metaplasia.

Eyeglasses are the most common form of eyewear used to correct or improve many types of vision problems. Contact lenses are worn directly on the cornea of the eye.

Detailed information on first aid for eyes and eye safety.

Detailed information on scabies, including symptoms, diagnosis, and treatment.

Detailed information on endocrine disorders

Detailed information on the most common eye disorders, including age-related macular degeneration, cataracts, diabetic retinopathy, glaucoma, refractive errors, and retinitis pigmentosa

Hypopituitarism is a disorder in which your pituitary gland does not make enough pituitary hormones. Learn more about this condition, including causes, symptoms, diagnosis, treatment, and when to contact your doctor.

Hypoparathyroidism occurs when 1 or more of your parathyroid glands are underactive. Here's what you need to know.

Detailed information on the most common skin inflammations (rashes), including atopic dermatitis (eczema), contact dermatitis, dermatitis herpetiformis, generalized exfoliative dermatitis, seborrheic dermatitis, localized scratch dermatitis, nummular derm

Hyperthyroidism means your thyroid gland is too active. Learn more about this condition, such as causes, symptoms, risk factors, diagnosis, treatment, and complications.