Fainting after a shower
18th Februrary 2023 | Dr Boon Lim
If you’ve wondered ‘why do I faint after a shower?’ you will find that you’re not alone. Many people prone to fainting can experience difficulty when or after taking a shower or a bath. Why do I faint in the shower? Is is because the water is too hot? Or because I am standing up for a long time? Perhaps its to do with me being dehydrated ?
Why Do You Faint?
The answer is all of the above! Fainting in the shower is a form of vasovagal syncope, with the underlying principles being almost identical to why you may faint whilst standing for long periods. Gravity usually causes blood to pool significantly in the lower limbs (which can serve as reservoirs of blood), and “remove” up to 1L of blood from your circulating volume of blood.
What happens specifically in the shower is that you are standing and venous pooling in the lower limbs will almost certainly be occurring to an extent.
However, the hot water will also result in additional blood pooling in your skin – which is the largest organ in the body! The combination of venous pooling in the lower limbs, as well as additional flushing (where blood pools in the skin as a response to a hot environment – where blood is diverted tot he skin as a means to help “cool off” the body), resulting ultimately in a drop in blood pressure with eventually leads to symptoms of light headedness and if uncorrected, a faint.
Having a hot bath
In essence, having a hot bath is akin to having a shower, as far as dilating the skin blood vessels is concerned. However, you are likely to only feel a little drowsy in the bath (but not lose consciousness), until the end of the bath, when attempting to get out of the bath. At this point, you add an additional layer of blood pooling within the lower limbs with gravity causing a further drop in blood pressure when trying to stand up to get out of the bath. This is when you are likely to feel extremely dizzy and may pass out!
Will I feel the same when having a spa?
If you are prone to fainting, you are likely to have exactly the same response when being in a hot spa, with worsening symptoms as you stand up after being seated or lying down for some time. This is exactly when you should be very careful, and recognise the need to get down to a seated or lying position immediately, to avoid injury.
In conclusion, experiencing fainting episodes in the shower, during a hot bath, or in a spa is not uncommon, and many individuals who are prone to fainting can relate to these situations. The phenomenon of vasovagal syncope explains why these events occur, with gravity causing blood pooling in the lower limbs, and the combination of hot water leading to additional blood pooling in the skin. The resulting drop in blood pressure can lead to light-headedness and, in severe cases, fainting. It’s important for individuals prone to fainting to be cautious and recognize the need to sit or lie down immediately when experiencing these symptoms to prevent potential injury. By understanding these triggers and taking appropriate precautions, individuals can better manage these situations and reduce the risk of fainting episodes.