What is pachyonychia congenita? Pachyonychia congenita is a very rare disorder. It causes thick nails and painful calluses on the bottoms of the feet. In some cases, blisters also form on the palms of the hands.
Is your back hurting? You’re in good company. In any 3-month period, about 1 in 4 adults in the U.S. has at least one day of back pain, mostly in the lower back. The back is a complicated structure. Its center is the spine, which is made up of 33 bones called vertebrae, stacked in a column. The nerves of the spinal cord run in a tunnel through the middle of those bones. Spongy discs between the vertebrae act as cushions. Ligaments and tendons hold everything together. A lot of things can go wrong with your back. A strained muscle