What should you know about hydrostatic pressure hydrotherapy?

Water presses gently around an immersed limb or trunk. This hydrostatic pressure can support the body and influence fluid movement, while buoyancy reduces the apparent load on joints. Warm water may also help muscles relax and make movement more comfortable. The depth of immersion changes the amount of support, so a physiotherapist can progress exercises by altering water level, speed, resistance, balance demands, or equipment.

Hydrotherapy can be part of care for joint pain or joint stiffness and may help people practise movement when land exercise is difficult. It may be considered alongside care for [Ankylosing Spondylitis](/conditions/ankylosing-spondylitis/), [Fibromyalgia](/conditions/fibromyalgia/), or [Frozen Shoulder](/conditions/frozen-shoulder/). Learn about the [Hydrotherapy Pool](/technology/hydrotherapy-pool/) and [Hydrotherapy](/treatments/physiotherapy-and-rehabilitation/hydrotherapy/).

A physiotherapist should screen your balance, walking ability, skin, breathing, heart symptoms, continence, and ability to enter and leave the pool. Wear suitable swim clothing and follow pool hygiene instructions. Start with controlled movements and report dizziness, unusual breathlessness, chest discomfort, or a sudden pain increase. The programme may include walking, joint mobility, strengthening, balance practice, and gradual transfer of gains to land-based [Exercise Therapy](/treatments/physiotherapy-and-rehabilitation/exercise-therapy/). Drink fluids and allow time to recover if fatigue is significant.

Do not enter the pool with an open wound, active skin infection, fever, or a new illness unless your clinician specifically clears it. Stop a session and seek help for chest pain, faintness, severe breathlessness, confusion, or sudden loss of strength. Tell the therapist about new swelling, a flare of pain, or problems with balance before the next session. People with uncontrolled heart or breathing conditions may need medical clearance and a tailored setting.

Ask whether water-based exercise fits your diagnosis, what pool temperature and depth are suitable, how you will enter and exit safely, and which symptoms mean you should stop. Ask how progress will be measured and when land exercise should be added.