Benton states that situs inversus, the reversal of the location of the internal organs, is very rare, being 1 in 1,000,000. He is right that it is rare, but it is a bit more common than once thought as most people with situs inversus have no symptoms and go their entire life without knowing they have the condition. The most recent statistics indicate that situs inversus is found in about 0.01% of the population, or 1 in 10,000. The most common form is situs inversus totalis, which is total transposition (right to left reversal) of all the visceral organs, the heart is on the right side of the chest instead of the left, and the liver on the left side instead of the right. An uncommon form of situs inversus is Isolated levocardia, which is where the heart remains in its normal position on the left side but the other visceral organs are reversed, this causes a high risk of heart defects and cardiac issues because the heart is often pressed up against what should be the right lung, which is larger than the left lung; it can also cause issues due to the liver being too close to the heart as well, these conditions often both require surgical intervention to put the organs back in their proper places.
