Taking a shower and washing your hair helps keep your body clean and relaxed. However, if not done properly, it can pose serious health risks. Below are 7 critical times you should absolutely avoid washing your hair to prevent sudden health issues.

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1. Washing Hair Early in the Morning

Washing your hair immediately after waking up can cause hair loss and headaches. Why? Because right after sleep, your blood circulation is still slow. Washing your hair at this time can lead to dizziness, headaches, catching a cold, or even fever.

Moreover, early morning temperatures are usually low. Washing your hair at this time may cause you to catch a severe chill, leading to dizziness, vertigo, or in extreme cases, a stroke. If you really need to wash your hair early, wait at least 30 minutes after waking up, use warm water, and dry your hair immediately afterward.

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2. Washing Hair When You Are Too Full or Too Hungry

Washing your hair right after a large meal or when you are very hungry can disrupt your digestion. This may lead to stomach pain, nausea, dizziness, and in severe cases, endanger your life. Your body’s energy is focused on digestion or is low due to hunger, so adding the stress of washing hair can cause complications.

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3. Washing Hair Late at Night

Many women suffer from chronic headaches or vertigo for years without realizing that one cause could be washing their hair late at night and not drying it properly before sleep.

Avoid washing your hair after 11 PM, and never go to bed with wet hair. Sleeping with damp hair impairs blood circulation and may trigger migraines or neurological headaches.

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4. Washing Hair When You Are Sick or Have a Fever

When your body is weak and your immune system is compromised during illness or fever, exposure to cold water or sudden temperature changes can worsen symptoms. Headaches may intensify, and you might catch a chill—a condition known in traditional Eastern medicine as “Phong Hàn” (wind-cold syndrome), which can be very dangerous and even life-threatening.

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5. Washing Hair During Menstruation

During menstruation, many women like to wash thoroughly to feel clean. However, studies show washing hair during this sensitive period can cause blood to rush away from the uterus to the scalp, disrupting blood flow in the reproductive organs. This may lead to incomplete menstrual discharge, reduced blood flow, and abdominal cramps.

Also, washing hair during menstruation can cause scalp blood vessels to dilate, making you more vulnerable to catching cold and headaches.

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6. Washing Hair Immediately After Exercise

After exercising, many want to wash off sweat right away. However, it's best to wait until your body cools down and sweat dries naturally before washing to avoid catching a chill or sudden illness.

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7. Washing Hair After Drinking Alcohol

Never wash your hair right after drinking alcohol. Doing so can cause dizziness, fainting, or vomiting. People with heart conditions should especially avoid cold water on their scalp after drinking.

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Additional Harmful Habits to Avoid When Bathing or Washing Hair:

1. Overusing Body Wash
Many body washes contain chemicals like lauryl amidopropyl betaine and BHT, which can penetrate skin quickly. Long-term excessive use can cause dryness, allergic dermatitis, and accumulation of harmful chemicals under the skin. Choose simple formulas and use a small amount each time.

2. Bathing with Water That’s Too Hot
Warm water is good for the body and helps prevent chills, but very hot water damages skin, dilates capillaries, and causes dryness and cracking. It also stresses the heart because all skin blood vessels dilate, reducing oxygen supply to the heart. The ideal bathing temperature in winter is between 24–29°C (75–84°F).

3. Washing Hair Before Body Wash or in the Wrong Order
The proper order is: wash your face, then your body, and finally your hair. If it’s winter, rinse your feet with warm water first to help your body adjust to the temperature. Don’t wash hair first and then body because sudden temperature changes can disrupt blood flow and cause dizziness.

4. Going to Sleep Immediately After Bathing
Hot water raises your body temperature and suppresses brain activity needed for deep sleep. Going to bed immediately after bathing makes it hard to fall asleep. Ideally, shower 1–2 hours before bedtime. If time is tight, simply wipe your forehead and neck with a cool damp towel for 5 minutes to normalize body temperature.

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Final Advice:

Understanding and avoiding these risky times and habits when washing hair and bathing can help you maintain your health and prevent sudden illnesses like stroke, migraines, and infections. Your body needs gentle care, especially during sensitive periods such as illness, menstruation, or after physical activity.