Why do my joints hurt when it rains?

You are not imagining it: weather-related joint pain is one of the most consistently reported patterns in medicine, even if science has not pinned down a single cause. The leading explanation involves barometric pressure - the weight of the air around you. Before rain, pressure typically falls, and lower outside pressure lets the tissues around a joint expand slightly. In a healthy joint you feel nothing; in a joint already stiff or inflamed by arthritis, that small expansion presses on nerves and an irritated joint lining, and you feel the forecast. Cold and damp add a second effect: muscles and tendons stiffen in low temperatures, making an arthritic joint ache more with movement. The honest science: studies have gone back and forth for decades, and the effect is real for many people but modest and variable - what is solid is the arthritis underneath. NHS guidance defines arthritis as pain, swelling and stiffness in one or more joints, with osteoarthritis (the most common type, usually starting in the late 40s, often in weight-bearing joints like knees and feet) and autoimmune types among the common forms. If weather-sensitive joints are a regular feature of your life, the answer is to treat the joint, not the forecast: keep moving, keep warm, and see a GP for a proper diagnosis - the NHS warns against self-diagnosing arthritis because the type decides the treatment. Pymander is a free AI doctor, 24/7 by text, that can help you track your pattern.