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
What is acne? Acne is a disorder that affects the skin’s oil glands and hair follicles. The small holes in your skin (pores) connect to oil glands under the skin. These glands make an oily substance called sebum. The pores connect to the glands by a canal called a follicle. Inside the follicles, oil carries dead skin cells to the surface of the skin. A thin hair also grows through the follicle and out to the skin. Sometimes, the hair, sebum, and skin cells clump together into a plug. The bacteria in the plug cause swelling. Then when the plug
What is osteonecrosis? Osteonecrosis is a bone disease. It results from the loss of blood supply to the bone. Without blood, the bone tissue dies. This causes the bone to collapse. It may also cause the joints that surround the bone to collapse. If you have osteonecrosis, you may have pain or be limited in your physical activity. Osteonecrosis can develop in any bone, most often in the: Thigh bone (femur). Upper arm bone (humerus). Knees. Shoulders. Ankles. It is also called: Avascular necrosis. Aseptic necrosis. Ischemic necrosis.
What is back pain? Back pain is one of the most common medical problems in the United States. It might feel like a dull, constant ache or a sudden, sharp pain. Back pain can result from: An accident. A fall. Lifting something heavy. Changes that happen in the spine as you age. A disorder or medical condition. Treatment depends on the cause and symptoms of your pain. You can do things to improve your health and lower your chance of developing chronic (long-lasting) back pain.