Which condition typically causes widespread muscle pain and can affect sleep?

Fibromyalgia is a condition that is characterized by widespread muscle pain and tenderness throughout the body. It is often associated with other symptoms such as fatigue, sleep disturbances, memory issues, and mood fluctuations. Patients with fibromyalgia frequently experience significant discomfort and may find it hard to maintain a restful sleep due to pain, leading to longer-term issues with sleep quality.

This condition is distinct because it not only causes physical pain but also impacts emotional well-being and cognitive function, commonly referred to as "fibro fog." While chronic fatigue syndrome is also linked to widespread pain and fatigue, its primary defining characteristic is severe fatigue that doesn't improve with rest, rather than the diverse symptom profile seen in fibromyalgia, where widespread pain and sleep disturbances are central features.

Multiple sclerosis and Parkinson's disease are neurological disorders that can involve muscle issues and pain but typically have a broader range of neurological symptoms and are diagnosed differently than fibromyalgia. Thus, fibromyalgia stands out as the correct answer because of its specific focus on widespread muscle pain and its notable effects on sleep.