As soon as I wake up
Many people have a habit of washing their hair in the morning to be more awake and have a beautiful hairstyle when going out. However, when you wake up in the morning, the blood circulation is still slow, the organs are not working smoothly, if you wash your hair right away, it can stimulate the brain blood vessels suddenly, causing you to have headaches and dizziness. Not to mention, in winter, low temperature, early morning shampoo can cause stroke. If you must wash your hair in the morning, do some gentle exercise first and then wash your hair at least 30 minutes after waking up. After washing your hair with warm water, you need to dry your hair immediately.
Late at night
After 9pm is not a good time to wash your hair. Washing your hair too late can cause headaches and vestibular disorders. Not to mention, going to bed with wet hair can impede blood circulation, leading to chronic headaches.
When too full or too hungry
Washing your hair when you are full can slow down the digestive process, causing stomach pain. Washing your hair when you are too hungry can cause nausea and dizziness. In particular, people with cardiovascular disease should not wash their hair when they are too hungry because it can make the disease worse due to ischemia.
Right after a workout
The habit of showering immediately after a workout helps to clean the skin and relax the muscles, giving a feeling of refreshment. However, do not wash your hair when your hair is still wet with sweat or your body temperature is high after exercise. Take time to rest to let your body cool down before taking a shower, limiting the risk of heat stroke, which can easily lead to a stroke.
When sick, fever
When sick, fever, the body’s immune function decreases, cold water can increase headaches, cause colds and aggravate illness.
Vienna (According to Healthline)