Kyphosis is forward rounding of the back.
Hunchback (kyphosis) usually refers to an abnormally curved spine. It's most common in older women and often related to osteoporosis.
Some people with kyphosis have back pain and stiffness. Others have no symptoms other than an exaggerated forward rounding of the back.
Studies have shown that using a smartphone can increase thoracic kyphosis, or a hunch in the upper back, while standing and walking. This can be caused by the unconscious forward curve of the neck that occurs when looking down at a phone to read emails, texts, or social media updates.