Japanese researchers have found that the incidence of stoke peaks at certain times of the day. They found the risk of a stroke peaks between 6 a.m. to 8 a.m. and 6 p.m. to 8 p.m. They felt that the body’s internal clock that regulates changes in the blood and circulation is the factor in the timing of this increased risk. They also found that the risk of an ischemic stroke (caused by a clot) was greatest in the morning, and for a hemorrhagic stroke (bleeding in the brain) was greatest in the afternoon.