Mindblown: a blog about philosophy.

The diagnosis, treatment, and prevention of diseases of the blood and bone marrow as well as of the immunologic, hemostatic (blood clotting) and vascular systems. Because of the nature of blood, the science of hematology profoundly affects the understanding of many diseases.

The proportion of the blood that consists of packed red blood cells. The hematocrit is expressed as a percentage by volume. The red cells are packed by centrifugation. For example, an hematocrit of 25% means that there are 25 milliliters of red blood cells in 100 milliliters of blood. The red cells make up a quarter of the…

Bright red blood in the stool, usually from the lower gastrointestinal tract — the colon or rectum — or from hemorrhoids. The term “hematochezia” is rarely used. “Bright red blood in the stool” is more widely used (and understood).

A worm classified as a parasite. (A parasite is a disease-causing organism that lives on or in a human or another animal and derives its nourishment from its host.) Lice are examples of parasites that live on humans; bacteria and viruses are examples of parasites that live either on humans or in humans; helminths are examples of parasites…

A bacterium that causes stomach inflammation (gastritis) and ulcers in the stomach and duodenum. This bacterium is the most common cause of ulcers worldwide. H. pylori infection may be acquired from contaminated food and water or through person-to-person contact. It is common in people who live in crowded conditions with poor sanitation. This bacterium is also believed…

Alternate Arabic term for cupping. The preferred Arabic term for this practice is al-hijamah.

Extreme nervousness. A term coined by the America cartoonist Billy DeBeck (1890-1942) in his comic strip Barney Google.

An abnormal, excessive, and persistent fear of pleasure. Sufferers with this most puritanical of phobias typically feel guilty about experiencing pleasure even though they usually realize rationally there is nothing at all wrong with taking pleasure. Their guilt usually arises from the fact that they are participating a pleasurable activity while others around them or…

Also known as giant cell pneumonia, this is a deadly but fortunately rare complication of measles. It tends to strike children who are immunodeficient as from leukemia or HIV/AIDS. The postmortem examination (autopsy) shows multinucleated giant cells lining the alveoli (air sacs) of the lungs. Named for the early 20th-century Austrian pathologist Victor Hecht.

Heat rash is an irritation of the skin that results from excessive sweating during hot and humid weather. Heat rash appears as clusters of red papules or blisters on the skin. It is more likely to occur on the neck and upper chest, in the groin, under the breasts, and in elbow creases. Children are more likely…