How Tall Can Humans Really Get?

Our upper limit for height, or genetic limit, is around 9 feet. To survive even for a few months at that height would be a bit of a miracle. In order to regularly produce people over 9 feet tall, the reproducing pair would probably need to be a different shape—not the usual human shape. This is because of the square-cube law. To put it simply, this law says that as a shape grows taller and taller, its volume increases at a much greater pace.

Extreme height is often caused by a pituitary gland tumor that produces excess growth hormone, known as acromegalic gigantism. The tumor prevents the release of sex hormones that normally limit bone growth, resulting in continuous growth. Very tall individuals face difficulties in movement and increased risks of blood pressure issues and infections, which can be fatal.