Does taking a hot bath increase blood pressure?
Generally, hot water doesn't raise blood pressure; on the contrary, it temporarily lowers it. When the body is exposed to heat, blood vessels near the skin's surface dilate to help the body dissipate heat. As blood vessels dilate, resistance to blood flow decreases, and blood pressure drops, according to the health website Verywell Health (USA).
People with high blood pressure should avoid taking excessively hot baths.
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A study published in the Canadian Medical Association Journal showed that soaking in a 40°C bath for 10 minutes can lower systolic blood pressure in people with high blood pressure during the soak. Therefore, people with high blood pressure don't necessarily need to avoid warm baths. What should be avoided is using water that is too hot or bathing for too long.
What's more worrying is low blood pressure.
For people with high blood pressure, taking a warm bath can lower blood pressure, but you shouldn't bathe in water that's too hot. High temperatures cause blood vessels to dilate. If the body is also dehydrated, or the person is taking blood pressure medication or diuretics, the blood pressure will drop even more.
If blood pressure drops too low, bathers may feel dizzy, weak, or lose their balance. When stepping out of the shower and standing up too quickly, blood temporarily pools in the legs, reducing blood flow to the brain for a few seconds. At that point, some people may experience lightheadedness or even faint.
When showering at night, avoid using water that is too hot.
If showering at night, people with high blood pressure should choose lukewarm water instead of hot water. This helps avoid blood pressure spikes that can cause dizziness or lightheadedness.
Generally, water temperatures around 37-38°C are considered warm, close to body temperature and comfortable. Around 39-40°C is considered quite hot. Water above 40°C is considered very hot and requires caution, especially for the elderly or those with cardiovascular disease or high blood pressure. If using a hot tub or soaking tub, even more caution is needed because the body is exposed to heat for a longer period.
Who should be more cautious when taking a warm bath?
People with high blood pressure who are otherwise well-controlled usually don't need to avoid warm baths. However, more caution is needed if blood pressure is consistently high, if you've ever experienced dizziness or fainting while bathing, if you have heart disease, or if you're taking medications that lower blood pressure.
Older adults should also be aware that the risk of losing balance and falling can increase when experiencing dizziness after showering. If you frequently feel dizzy when standing up after showering, you should talk to your doctor instead of self-medicating or trying to endure the symptoms, according to Verywell Health .