As the blood vessels near the surface of the facial skin enlarge to help cool an individual, the face flushes red, explains WebMD. While the exact cause of hot flashes is not known as of 2015, experts believe that changes in circulation play a role. A hot flash is a sudden feeling of intense heat, sometimes accompanied by sweating and an increased heart rate. A hot flush usually refers to a simultaneous redness in the face and neck.
Researchers believe that a reduction in estrogen causes the hot flashes that affect approximately 85 percent of menopausal women, according to Drugs.com. This hormonal decrease affects the brain’s hypothalamus, the gland responsible for keeping the body’s temperature in balance. A hot flash in progress alerts the hypothalamus to the presence of excess heat, which triggers an attempt to cool the individual by dilating the blood vessels near the skin of the upper body. Some women experience only a few hot flashes in a year; others undergo dozens in a day.
Men with low testosterone levels are also susceptible to hot flashes, according to Drugs.com. Seventy-five percent of men who undergo an orchiectomy, or removal of the testes, to treat prostate cancer experience hot flashes, as do men who take testosterone-reducing medications. Individuals with tumors of the pituitary or hypothalamus glands and those with thyroid disease are also prone to hot-flash-like symptoms.