Explore · Understand · Check the source
Patient-friendly health topic summaries from the US National Library of Medicine.
Huntington's disease (HD) is an inherited disease that causes certain nerve cells in the brain to waste away. People are born with the defective gene, but symptoms usually don't appear until middle age. Early symptoms of HD may…
Your liver is the largest organ inside your body. It helps your body digest food, store energy, and remove poisons. Primary liver cancer starts in the liver. Metastatic liver cancer starts somewhere else and spreads to your liver.…
The cornea and lens of your eye bend (refract) light rays to focus them on the retina. Refractive errors happen when the shape of your eye prevents light from focusing correctly on the retina. This causes blurry vision. Changes in the…
Respiratory failure is a condition in which your blood doesn't have enough oxygen or has too much carbon dioxide. Sometimes you can have both problems. When you breathe, your lungs take in oxygen. The oxygen passes into your blood,…
Each reference identifies its source, coverage and retrieval date. Full text is shown only where reuse is permitted; some entries are terminology or bibliographic records. Sources and coverage.