Balneotherapy refers to the medical use of mineral-rich spa waters and mud treatments for therapeutic purposes. It involves soaking, bathing, or applying heated mud and water to the body, which can help stimulate blood circulation and treat symptoms of certain diseases like arthritis. Common minerals found in spa waters that may provide benefits include sodium, magnesium, calcium, iron, and others. While balneotherapy has shown potential for improving certain rheumatological diseases, more rigorous research is still needed to fully understand its effectiveness.