(A) Because blood vessels contract with cold.
(B) Because blood flow becomes faster with cold.
A5. (A) Because blood vessels contract with cold.
Blood plays a very important roll to control the body temperature. For example, when you go to a warm place, your body tries to release heat enlarging the blood vessels to lower the body temperature. On the contrary, when you go to a cold place, your body tries not to release heat contracting the blood vessels to keep the body temperature. This is similar to the relationship between cars and roads. Assuming the warm place is 3 lanes and the cold place is 1 lane, when cars come from 3 lanes to 1 lane, traffic jam happens at 1 lane. That is like blood tends to be clogged if it is cold because the blood vessel becomes narrower. That is why stroke and heart attack tend to occur more in January and February (winter).
Q6. Who has the risk to have stroke or heart attack (myocardial infarction) during sleep?
(A) A person who snores
(B) A person who talks in his or her sleep
(C) A person who often tosses and turns
A6. (A) A person who snores
Q7. Why does the person who snores during sleep have the risk?
A7. Because blood pressure goes up and down repeatedly, applying a burden to the blood vessels.
Rapid rise of blood pressure applies a burden to the blood vessels and there is a high possibility that it damages the blood vessels. A person who snores frequently has a high possibility to cause sleep apnea syndrome. When snoring starts, blood pressure goes up and when snoring stops, blood pressure goes down so every time snoring starts and stops, snoring puts a tax on the blood vessels.
Q8. Heart attack (Myocardial infarction) tends to occur in the morning, especially within an hour after waking up. What are dangerous habits if they are done especially on cold morning?
A8. Going to the bathroom, washing one’s face, taking out the garbage, taking the dog for a walk, jogging, etc.
So what are the reasons that they are dangerous habits? First, cold morning makes the blood vessels contract, leading to the rise of blood pressure. That is why it is dangerous. Straining to defecate leads to the rise of blood pressure. If you jog or take the dog for a walk dressed lightly on a cold morning, blood pressure goes up by coldness and exercises. So when you take the dog for a walk, it is important to protect yourself against the cold wearing a scarf and a coat. It is very dangerous to let your guard down, thinking it is OK because it is very short time.