Syncope is the loss of consciousness (fainting) caused by decreased blood flow to the brain. According to the Cleveland Clinic, this condition often results from a sudden decrease in blood pressure, blood volume changes or a lowered heart rate.
In addition to hypotension (low blood pressure), medical conditions such as anemia, metabolic or autonomic nervous system abnormalities and circulation and heart problems can cause syncope.
Syncopal episodes can also be caused by a particularly painful or unpleasant occurrence, such as the sight of blood, standing in the sun or standing in a hot shower for a long time. Particularly if you are hungry or dehydrated and decide to take a hot shower, this could increase your risk of experiencing syncope.
Although syncope can occur in people with no abnormalities, it is important to determine its cause to rule out serious medical conditions.
Hypotension, or low blood pressure, is a common cause of syncope. Fainting occurs when the person changes position by standing or sitting, causing blood to pool in the lower extremities (below the diaphragm).
In addition to fainting during a hot shower, susceptible individuals may experience syncope when sitting for long periods of time, after exercise and after eating a large meal.
Symptoms and Detection of Hypotension
Recurrent lightheadedness as well as chronic fatigue after modest amounts of exercise is common in cases of syncope. Symptoms of chronic confusion, dizziness, and being in a “mental fog” often precede syncope.
This may result from a miscommunication between the heart and brain, the result being not enough blood flow to the brain. A routine blood pressure test will not detect this condition; a “tilt” test is needed.
The tilt test measures blood pressure and heart rate while keeping patients in an upright position for an extended amount of time.
Causes of Fainting During Hot Showers
During a hot shower, the body tries to cool itself by dilating its blood vessels. This results in less blood flow to the brain, resulting in light-headedness, dizziness and syncope.
The elderly are more susceptible to syncope, because their blood vessels are less elastic. Therefore, they are more likely to faint when their blood pressure drops or when their blood circulation changes.
In addition, factors such as hypoglycemia (low blood sugar) or dehydration will make individuals more susceptible to fainting during a hot shower.
Tips for Taking Hot Showers
There are a few key ways to prevent syncope if you're taking a hot shower. First, try using lukewarm or even cold water when you shower; most doctors recommend keeping water below 110 degrees.
Prevent steam from building up in the shower by opening a bathroom window or door. Limit time spent in hot showers to five minutes; or, if taking long showers, come out of the shower every five minutes.
You could also use a vent fan; this is a helpful way to prevent your bathroom from getting too hot.
If you do feel faint after a hot shower, lying flat on the floor or with the legs slightly elevated promotes blood flow back to the head.