Explore comprehensive guides on hundreds of common and rare diseases and conditions from the experts at Mayo Clinic.

Jun 13, 2020 · Pneumonia is an infection that inflames the air sacs in one or both lungs. The air sacs may fill with fluid or pus (purulent material), causing cough with phlegm or pus, fever, chills, and …

Jan 25, 2025 · Overview Dystonia is a movement disorder that causes the muscles to contract. This can cause twisting motions or other movements that happen repeatedly and that aren't under the …

Retinal detachment is an emergency situation in which the thin layer of tissue at the back of the eye, called the retina, pulls away from its usual position. Retinal cells separate from the layer of blood …

Feb 22, 2024 · Sacroiliitis (say-kroe-il-e-I-tis) is a painful condition that affects one or both sacroiliac joints. These joints sit where the lower spine and pelvis meet. Sacroiliitis can cause pain and …

Oral lichen planus (LIE-kun PLAY-nus) is an ongoing inflammatory condition that affects mucous membranes inside the mouth. There are several different types of lichen planus that affect the …

Mar 7, 2025 · This condition affects children and may continue into adulthood. It can include having a hard time paying attention, being hyperactive and being impulsive.

Apr 30, 2025 · Salmonella infection (salmonellosis) is a common bacterial disease that affects the intestinal tract. Salmonella bacteria typically live in animal and human intestines and are shed …

Feb 9, 2023 · Learn about possible causes and treatments for breast pain, along with self-care remedies that may help keep you comfortable when breast pain flares.

Jul 18, 2025 · A herniated disk, which can occur in any part of the spine, most often occurs in the lower back. Depending on where the herniated disk is, it can result in pain, numbness or weakness in an …