Hydrotherapy — exercise in warm water, typically 33–36°C — is one of the most effective and enjoyable treatments for arthritis. The combination of warmth, buoyancy and water resistance creates an ideal exercise environment where joints can move freely with minimal pain. Recommended by NICE, the NHS and Versus Arthritis, hydrotherapy has a strong evidence base for improving pain, stiffness, strength and function in both osteoarthritis and inflammatory arthritis. This guide explains the benefits, helps you access NHS hydrotherapy services and tells you what to expect.
Quick answer: Hydrotherapy is exercising in warm water, typically 33–36°C, helping arthritis by reducing body weight, allowing easier movement. The warmth relaxes muscles and lessens pain, while water resistance builds strength. NHS sessions, usually 30–45 minutes, are led by a physiotherapist, with courses often lasting 6–12 weeks. Access is usually via GP or rheumatologist referral.
How Hydrotherapy Helps Arthritis
Buoyancy
When immersed to waist depth, your body weight is reduced by approximately 50%. At chest depth, weight-bearing stress is reduced by up to 80%. This allows movements that would be painful on land to be performed with significantly less joint loading. People who struggle to walk comfortably on land often find they can walk, squat and exercise freely in water.
Warmth
Hydrotherapy pools are heated to 33–36°C (compared to standard swimming pools at 26–28°C). This warmth relaxes muscles, increases blood flow to joints, reduces pain perception and improves the elasticity of connective tissues. Many people describe the immediate relief of entering warm water as one of the most pleasant experiences of their arthritis management.
Hydrostatic Pressure
The pressure of water around the body reduces swelling in joints and limbs, provides support during movement, and improves circulation. This is particularly beneficial for people with swollen ankles, knees or hands.
Resistance
Water provides natural resistance to movement — approximately 12 times more resistance than air. This means exercises performed in water provide muscle strengthening without the need for weights or equipment. The resistance is proportional to speed, so you can control the intensity simply by moving faster or slower.
What the Evidence Says
- A Cochrane review found aquatic exercise significantly improved pain, function and quality of life in knee and hip OA
- Research published in Physical Therapy found hydrotherapy produced greater improvements in pain and function than land-based exercise for knee OA
- A systematic review in Rheumatology found that aquatic exercise was beneficial for RA, improving joint tenderness, mood and overall well-being
- NICE recommends hydrotherapy as part of multimodal management for OA
- Benefits typically appear within 4–6 weeks of regular sessions
What Happens in a Hydrotherapy Session
A typical NHS hydrotherapy session lasts 30–45 minutes and is led by a physiotherapist or specialist hydrotherapy assistant:
- Assessment — Before your first session, a physiotherapist will assess your joints, mobility and goals
- Warm-up — Gentle walking and arm movements in the water
- Exercises — Tailored exercises targeting your specific joints — may include walking, squats, leg lifts, arm exercises, stretches and balance work
- Cool-down — Gentle stretches and relaxation in the warm water
Sessions may be individual (one-to-one with a therapist) or group-based (typically 4–8 people). Group sessions are social and motivating, while individual sessions allow more tailored exercises.
Accessing NHS Hydrotherapy
- GP referral — Ask your GP to refer you to physiotherapy, specifically requesting hydrotherapy if available locally
- Direct physiotherapy referral — Many NHS trusts accept self-referrals to physiotherapy
- Rheumatology team — If you're under a rheumatologist, they can refer directly to hydrotherapy
- Waiting times — Typically 4–12 weeks, though this varies by area
- Course length — Usually 6–12 sessions
Finding Hydrotherapy Pools
Dedicated hydrotherapy pools exist at many NHS hospitals, community health centres, some private physiotherapy clinics and charity facilities (Versus Arthritis lists some). Not all areas have easy access — if NHS hydrotherapy is unavailable, many public leisure centres offer "warm water" or "gentle aqua" sessions in pools heated to higher temperatures than standard.
Private Hydrotherapy
Private hydrotherapy sessions typically cost £40–£80 per session. Some private health insurance covers hydrotherapy with a GP or consultant referral. Private sessions usually have shorter waiting times and more flexibility in scheduling.
Swimming vs Hydrotherapy
While both involve water, they differ significantly. Hydrotherapy pools are warmer (33–36°C vs 26–28°C), smaller and shallower with easy access (ramps, hoists). Sessions are supervised and exercises tailored to individual needs. Standard swimming is excellent exercise for arthritis but doesn't provide the same therapeutic warmth. Both are beneficial — hydrotherapy is typically more appropriate for those with severe symptoms, while regular swimming maintains fitness once symptoms are better controlled.
Tips for Getting the Most from Hydrotherapy
- Continue your exercises at home between sessions — your physiotherapist will give you a home programme
- Arrive early to shower and change at a relaxed pace
- Bring a water bottle — you can get dehydrated in warm water without realising
- Rest afterwards if needed — warm-water exercise can be tiring initially
- After your NHS course ends, continue with public pool sessions to maintain benefits
Hydrotherapy is one of the most effective and enjoyable treatments available for arthritis. If you haven't tried it, ask your GP about access. Our virtual assistant can help you find hydrotherapy pools and warm-water exercise classes near you.
This article is for general information only. Hydrotherapy may not be suitable if you have certain medical conditions (uncontrolled blood pressure, open wounds, certain infections). Your physiotherapist will assess suitability.
Practical next steps for Hydrotherapy for Arthritis UK: Benefits, Access and What to Expect
If you came here about Hydrotherapy for Arthritis UK: Benefits, Access and What to Expect, pick one change you can keep for a fortnight rather than overhauling everything at once. Note what hurts, what helps, and what you have already tried, then take that list to your GP, rheumatology nurse or physiotherapist so the conversation stays concrete.In many areas you can ask community musculoskeletal services about self-referral to physiotherapy or lifestyle support without waiting for a hospital letter. Check your GP surgery website or the NHS App for the route that applies where you live.
Building a joint-friendly routine
Start with short sessions you can repeat on most days. Warm water, cycling, or paced walking often suits stiff joints better than sudden high-impact bursts. Increase time or resistance slowly, and leave a rest day when a joint is hot, swollen or unusually painful. If you are unsure where to begin, ask about NHS physiotherapy or an exercise referral scheme via your GP surgery.
Pacing on good and bad days
On better days it is tempting to catch up on everything at once. Spread chores and exercise across the week instead. Use the two-hour rule many physiotherapists suggest: if pain or fatigue is clearly worse two hours after activity, the dose was too high — trim the next session rather than stopping altogether.
Work, rights and practical adjustments
Under the Equality Act 2010, employers in Great Britain should consider reasonable adjustments when arthritis has a substantial long-term effect. That can mean flexible hours, more breaks, seating, parking closer to the entrance, or software that reduces typing strain. Acas and Citizens Advice both publish plain-English guides you can take into a meeting.
Benefits conversations
Personal Independence Payment (PIP) looks at how your condition affects daily living and mobility, not the diagnosis name alone. Keep a short diary of bad days, help you need with dressing or cooking, and walking limits. Welfare rights advisers at local councils or charities can check forms before you submit them.
Working with NHS pathways
Most people start with GP care, community physiotherapy and self-management, with rheumatology involved when inflammatory disease is suspected or treatment needs escalate. Ask what monitoring blood tests or reviews you should expect, and who to contact between appointments if a flare escalates.
Preparing for appointments
Write three priorities before you go: main symptom, functional limit (stairs, sleep, work), and the question you most need answered. Bring a current medicine list including over-the-counter products. If English is not your first language, request an interpreter when you book.
Quick questions about Hydrotherapy Arthritis Benefits Access
Is this a substitute for seeing a clinician? No. Use it to prepare questions and understand options, then confirm decisions with your NHS team.How long before I judge whether a change helped? Give most habit or exercise changes at least two to four weeks, unless pain or swelling clearly worsens — in that case scale back sooner.
What should I track? Joint pain (0–10), morning stiffness time, sleep quality, and how far you can walk or how long you can type or stand. Patterns beat one-off ratings.
Safety and when to get urgent help
This page is general information for people in the United Kingdom, not personal medical advice. Seek urgent help via NHS 111 or A&E if you have sudden inability to move a joint, hot swollen joint with fever, chest pain, severe shortness of breath, or symptoms that feel immediately dangerous.
Keep learning with us
Explore related guides on Living With Arthritis UK — try the guides hub, diet hub, exercise hub, or site search to filter by topic and length. If benefits or work questions are on your mind, start at the Benefits & PIP hub.
Continue reading
- Physiotherapy for Arthritis — How It Helps & Access — Everything you need to know about physiotherapy for arthritis: what it involves, NHS self-referral, private costs, hydrotherapy, and.
- Hydrotherapy Pools UK – Find Warm Water Therapy Near You — Find NHS and community hydrotherapy pools across the UK.
- Walking Aids for Arthritis UK – Sticks & Daily Aids — Complete UK guide to walking aids and daily living gadgets for arthritis.
- Aquatic Therapy for Arthritis: More Than Just Swimming — Hydrotherapy and aquatic exercise provide unique benefits for arthritis.