Sleep Apnea
American scientists say they have found the strongest evidence yet
linking a breathing problem called sleep apnea to high blood pressure.
They published the study in the Journal of the American Medical Association.
People with sleep apnea briefly stop breathing while they sleep.
Sleep apnea can cause a tired feeling and head pain.
Researchers at the Johns Hopkins University School of Public Health organized the new study.
It involved more than 6,000 adults.
The researchers found that people who stopped breathing the most during sleep were more likely to have high blood pressure.
Even people with moderate levels of sleep apnea had a higher risk of high blood pressure.
High blood pressure increases the risk of heart attack, stroke and kidney disease.
Sleep apnea is more common among people who weigh too much.
However, the study found a link between sleep apnea and high blood pressure in people of all weight groups.
Experts say people with high blood pressure who become sleepy during the day should be tested for sleep problems.
It is not clear yet if sleep apnea causes high blood pressure.