On a December morning in 2013, this Metro-North train headed towards New York City derailed in the Bronx, killing four passengers and injuring 115. The driver was later found to have severe sleep apnea. This wasnât the first incident involving trains or the last. Learn more.
Arm pain can be caused by a wide variety of problems, ranging from joint injuries to compressed nerves. Depending on the cause, arm pain can start suddenly or develop over time. In many cases, arm pain actually originates from a problem in your neck or upper spine. Arm pain, particularly pain that radiates into your left arm, can even be a sign of a heart attack. Causes.
Common arm problems that are not caused by a specific injury, such as a blow or fall, include the following: 1  Overuse or repetitive-motion injuries occur when you overdo an activity or repeat the same activity. The repeated activity may stress joints or other tissues and cause pain and swelling.