Muscle pain can be a common symptom in some health conditions, including some mentioned below. It is always important to be aware of how your body responds to your environment and your activity. Notice if you see any changes, swelling, or other accompanying symptoms which may point to a health condition that needs attention. Here are some health conditions that may cause muscle pain and need to be diagnosed if severe. Chronic fatigue This is a chronic condition in which the person feels extremely tired for a long period, like 6 months, without any reasonable explanation for this tiredness. The fatigue tends to increase with any physical or mental activity. However, even with adequate rest, the tiredness does not go away. Muscle or joint pain is a common symptom of chronic fatigue, along with unrefreshing sleep, sore throat, headaches, loss of concentration or memory, and dizziness from lying down or standing up quickly. Chronic fatigue causes are viral infections, hormonal imbalance, immune system problems, or even physical or emotional trauma. Muscle cramp This condition refers to a sudden or involuntary contraction of one or more muscles in the body leading to tightness or stiffness, causing discomfort. Some people also experience cramps during sleep and are awake due to the sudden pain felt in the muscle.