Pain in a dream often represents a struggle in waking life, stress and unpleasantness. It can also serve as an unconscious warning from your subconscious mind that something bad is about to happen.
Running out of energy at the end of the day that continues onto your dreams can be blood pressure related and lead to signs like water retention. Falling asleep with head, body and limbs tired from exhaustion can cause more pain in a dream than what you might be experiencing normally.
Also, pain in a dream can mean fear, sadness, stress, and many other negative emotions that you feel during waking hours.