5. Pending Infection
Even though it might not be considered to be one of the most common causes of pain felt in the left arm, a pending infection should be considered as one of the possible signs and symptoms. If you have any kind of infection in your body, it can lead to pain anywhere and what feels like everywhere in the body.
Fever is one of the first symptoms of a possible infection or inflammation somewhere in the body, and this often comes with the associated feeling that your skin has been set on fire. Sometimes the affected person will feel unusually hot or cold at the same time. This can be coupled with pain in the left arm, though sometimes throughout the whole body.
Certain over-the-counter medications can bring a fever under control (such as paracetamol), though see a doctor to treat the underlying infection – and definitely see a doctor if fever persists for several hours at a time.