(HealthDay News) -- Fainting occurs when you temporarily lose consciousness because of a sudden drop in blood flow to the brain.

(HealthDay News) -- Cyberbullying involves harassing, threatening or embarrassing young people through the use of technology, such as computers (especially Facebook) or cell phones.

TUESDAY, Aug. 9 (HealthDay News) -- As parents prepare to send their children back to school, they need to remember that nutrition is an important factor in academic performance, an expert advises.

TUESDAY, Aug. 9 (HealthDay News) -- People who regularly eat legumes, brown rice, cooked green vegetables and dried fruit have a reduced risk of colon polyps, a precursor to colon cancer.

TUESDAY, Aug. 9 (HealthDay News) -- Kids' meals at fast-food restaurants are high in fat, calories and sodium, a new study shows.

TUESDAY, Aug. 9 (HealthDay News) -- One-third of people who survive a nearly fatal subarachnoid hemorrhage -- a type of stroke that involves bleeding into the brain -- experience the symptoms of post-traumatic stress disorder (PTSD), researchers have found.

TUESDAY, Aug. 9 (HealthDay News) -- Good knowledge of hand hygiene among students reduces school absenteeism, researchers report.

TUESDAY, Aug. 9 (HealthDay News) -- Motion sickness on the world's tilting trains could be eliminated by changing the way cars take curves, researchers say.

TUESDAY, Aug. 9 (HealthDay News) -- Children with poorly controlled asthma face significantly higher medical costs and miss many more school days than kids with asthma that is better managed, a new study indicates.

TUESDAY, Aug. 9 (HealthDay News) -- People with low lifetime levels of physical activity are at increased risk for peripheral artery disease (PAD), a new study has found.

MONDAY, Aug. 8 (HealthDay News) -- Countering conventional wisdom, researchers in France say that elderly lung cancer patients can gain significant benefit from an aggressive, double-barreled chemotherapy that's often used in younger patients.

TUESDAY, Aug. 9 (HealthDay News) -- New research indicates that up to half of human intelligence can be explained by genetics, but this involves small contributions by many different genes and not one overarching "smart" gene.

Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:

TUESDAY, Aug. 9 (HealthDay News) -- Key factors that affect a child's risk of developing allergies by age 2 include race, a mother's exposure to pets during pregnancy and the method of delivery, a new study suggests.

TUESDAY, Aug. 9 (HealthDay News) -- A new study appears to upend the long-held belief that black patients with kidney failure do better on dialysis than whites.

TUESDAY, Aug. 9 (HealthDay News) -- With headlines using words like "plummet" and "dive" to describe steep stock market declines this week, experts say many Americans' emotions are also in a downward spiral.

TUESDAY, Aug. 9 (HealthDay News) -- Elderly women who experience sleep apnea have a higher risk of developing mild cognitive impairment or dementia, new research finds.

TUESDAY, Aug. 9 (HealthDay News) -- When an older man's wife or girlfriend has a stronger bond with his friends than he does, his performance in the bedroom tends to suffer, a new study shows.

TUESDAY, Aug. 9 (HealthDay News) -- A simple blood test from mom can spot the sex of a fetus as early as seven weeks into a pregnancy, researchers report.