A sharp back pain can be a symptom of a more serious condition, or it may be the result of a muscle spasm. A muscle spasm occurs when a muscle tightens suddenly, causing a painful sensation wherever the tension is happening. They often occur after some sort of impact or unexpected strain, though they also can happen after long periods of sitting or standing. In the lower back, a sharp back pain may be caused by sciatica. More serious conditions that cause sharp back pain might include anything from a heart attack to pneumonia, or a herniated disc in the spine.
Sciatica is perhaps the most common cause of sharp back pain. This type of pain occurs when the sciatic nerve, which runs from the lower back to the bottom of the legs, becomes pinched between muscles, or between bones. When the nerve gets pinched, a sharp back pain may be felt, or a sharp, shooting pain in the hips, buttocks, or the backs of the legs. If the nerve is pinched because of a herniated disc in the spine, medical attention may be required. If the nerve is pinched because of tightness in the muscles of the lower back, buttocks, hips, or legs, regular stretching and exercise should be sufficient to alleviate the pain and prevent it from happening again.
During physical activity, particularly during sports, muscle spasms are common. The muscle tenses suddenly because an unexpected load or impact has been placed upon it. The muscle may tense to prevent further injury to the body, particularly the spine, as well. The spasm may cause a sharp back pain anywhere along the spine, and it usually takes a bit of rest and stretching to alleviate the pain. Anti-inflammatory medication can also be used for pain relief. A muscle strain may cause soreness or tenderness for hours or even days after the injury. Sufficient time should be granted for rest and recovery.
Other types of sharp back pain might not be caused by anything in the back. It may be a symptom of another, more serious condition, such as a heart attack or pneumonia, especially if the pain occurs suddenly. The pain from a heart attack tends to radiate, meaning it can often be felt in the back between the shoulder blades. Conditions such as kidney stones also tend to radiate pain, and may be felt in the lower and middle back.