Left arm pain and dizziness?

See below. At your age neck pain that runs down the arm with or without spasms and heaviness sounds like a pinched nerve in the neck. This is usually caused by a protruding disc or bone spur touching one of your spinal nerves as it leaves your neck. Sometimes arm pain could be related to your heart or other conditions. See your physician soon for workup.
Possible emergency . Atypical heart pain can be manifest, as arm pain, esp if combined with other symptoms. Do you have other risk factors. Seek medical attention now.