Clinically referred to as myalgia , muscle pain is an ache that occurs in your ligaments, soft tissues, or tendons that connect your bones and muscles. This pain may be limited to one area of the body or spread over a group of muscles. While in most cases, these cramps and pains resolve on their own, they can sometimes be a symptom of an underlying health condition. These conditions are known to cause muscle pain: Fibromyalgia Fibromyalgia is a chronic illness that is commonly known to cause cramps and muscle pain. This disorder amplifies how your spinal cord and brain process pain sensations. The muscle aches associated with this condition usually cause widespread dull pain on both sides of your body, particularly below the waist. Such an issue may often lead to sleep disorders and daytime fatigue. Fibromyalgia is usually caused by repeated nerve stimulation, which changes the levels of certain chemicals that indicate pain. Some common reasons for this are Genetics Chronic stress Physical trauma and injuries Conditions such as lupus or osteoarthritis Illnesses like Lyme disease Infections like HIV Fibromyalgia is treated by administering painkillers or an XL Patch. Physical and occupational therapy also helps in relieving painful muscles.