Hydrotherapy for Arthritis: A Complete Evidence-Based Guide
Key Takeaways
- A 2024 meta-analysis of randomised controlled trials found hydrotherapy significantly reduces pain and improves physical function in knee osteoarthritis patients, with mean improvements of 6.5 and 10.5 points for pain and physical function respectively — and no serious adverse events reported [2].
- Hydrotherapy outperforms land-based exercise for pain relief before and after walking in people with knee osteoarthritis (Hinman et al., 2007) [3].
- Water buoyancy reduces the load on your joints by 50-75% depending on immersion depth, allowing movement that would be painful or impossible on land.
- A structured 4-week hydrotherapy programme significantly decreased pain and improved functional status in older women with knee osteoarthritis (Tomas-Carus et al., 2017) [4].
- A large-scale review of 32 RCTs involving over 2,200 participants confirms the efficacy of aquatic exercise for chronic musculoskeletal disorders broadly [6].
- Hydrotherapy benefits people with osteoarthritis, rheumatoid arthritis, fibromyalgia, and gout — though the mechanisms and approach differ for each.
Arthritis does not just affect your joints. It reshapes your entire relationship with movement. The stiffness that greets you every morning. The way you calculate whether a walk is worth the pain it will cost you later. The slow retreat from activities you used to do without thinking.
If that sounds familiar, you are not alone. And you are not stuck.
Hydrotherapy — structured exercise and immersion in warm water — is one of the most thoroughly researched, low-risk treatments available for arthritis. Not as a miracle cure (nothing is), but as a practical, sustainable way to move more, hurt less, and reclaim some of what arthritis has taken from your daily life.
This guide covers what the clinical evidence actually says, which types of arthritis respond best, specific exercises you can try in the water, and how to build a realistic programme whether you have access to a therapy pool or just a bathtub at home.
Why Water Is Ideal for Arthritic Joints
To understand why hydrotherapy works so well for arthritis, you need to understand three properties of water that work in your favour the moment you step in.
Buoyancy Removes the Weight
When you stand in waist-deep water, buoyancy offloads roughly 50% of your body weight from your joints. Move to chest depth, and that figure rises to approximately 75%. If you weigh 80 kilograms on land, your knees and hips may bear as little as 20 kilograms in the pool.
That reduction is transformative for arthritic joints. Cartilage that has worn thin in osteoarthritis gets a reprieve from grinding. Inflamed synovial membranes in rheumatoid arthritis are spared the mechanical stress that worsens swelling. You can walk, bend, and squat in water in ways that would be impossible or agonising on dry ground.
Warm Water Softens Stiffness
Most hydrotherapy pools are heated to 33-36 degrees Celsius (approximately 92-97 degrees Fahrenheit). The Arthritis Foundation recommends water between 92-100 degrees Fahrenheit (33-38 degrees Celsius) for therapeutic benefit. That warmth dilates blood vessels, increases circulation to joint tissues, and relaxes the muscles that reflexively tighten around painful joints. If morning stiffness is your worst symptom, warm water is a direct counter to it.
Resistance Builds Strength Without Strain
Water is roughly 12 times more resistant than air. Every movement you make in a pool strengthens the muscles that support your joints. But unlike a gym, water resistance is self-regulating: it only pushes back proportionally to how hard you push. Move slowly for gentle mobilisation. Move faster for genuine strengthening. You control the intensity moment to moment, making it nearly impossible to accidentally overload a vulnerable joint.
For a deeper look at these mechanisms, our article on the science behind hydrotherapy covers the physiology in detail.
Which Types of Arthritis Respond to Hydrotherapy?
Not all arthritis is the same, and the way hydrotherapy helps varies depending on your specific condition.
Osteoarthritis (OA)
Osteoarthritis — the “wear and tear” type — has the deepest evidence base for hydrotherapy. The degeneration of cartilage in weight-bearing joints like knees and hips means that any reduction in joint loading during exercise is a significant advantage. Hinman et al. (2007) demonstrated that hydrotherapy was superior to conventional land-based exercise for reducing pain before and after walking in knee OA patients [3]. The 2024 meta-analysis confirmed these findings across multiple trials, reporting mean improvements of 6.5 points for pain and 10.5 points for physical function on standardised scales [2].
The combination of buoyancy (less load), warmth (less stiffness), and resistance (stronger supporting muscles) addresses all three core problems of OA simultaneously.
Rheumatoid Arthritis (RA)
Rheumatoid arthritis is an autoimmune condition where the body attacks its own joint linings, causing inflammation, swelling, and pain that can affect any joint. A Cochrane-affiliated systematic review (2012) examined hydrotherapy specifically for RA and found consistent evidence of benefit for pain reduction and functional improvement [1].
The key difference with RA is that it involves systemic inflammation, so timing matters. During stable periods, regular hydrotherapy can maintain joint mobility and muscle strength. During active flares, gentler warm-water immersion without vigorous exercise may be more appropriate. Warm water still helps by relaxing muscles, reducing stiffness, and providing the psychological relief of being able to move comfortably.
Fibromyalgia
Fibromyalgia is not technically arthritis, but it produces widespread musculoskeletal pain and is often managed alongside arthritic conditions. People with fibromyalgia frequently have heightened pain sensitivity, and the pressure of land-based exercise can trigger flare-ups. Water provides a gentler environment. The buoyancy reduces pressure on tender points, the warmth eases pervasive muscle tension, and the sensory input of water can have a calming effect on an overactive nervous system. Hall et al. (2007) studied hydrotherapy classes alongside other physical activity approaches and found hydrotherapy to be a viable option for managing chronic musculoskeletal pain [5].
Gout
Gout is an inflammatory arthritis caused by uric acid crystal deposits in joints, most commonly the big toe. During acute gout attacks, joints can be extremely hot, swollen, and exquisitely tender — and vigorous hydrotherapy is not appropriate during these episodes. However, between flares, gentle warm-water exercise can help maintain joint mobility and overall fitness, which supports long-term gout management. The approach should be conservative: warm (not hot) water, gentle movements, and close attention to how the affected joints respond.
What the Research Says: Condition by Condition
Vague claims about hydrotherapy “helping” are not useful. Here are specific findings from clinical trials and systematic reviews.
Hydrotherapy Beats Land-Based Exercise for Knee OA Pain
Hinman and colleagues (2007) conducted a single-blind randomised controlled trial comparing hydrotherapy directly to conventional land-based exercise for hip and knee osteoarthritis. The finding that matters most: hydrotherapy was superior for reducing pain both before and after walking. Both groups improved compared to a control group, but the water-based group had a clear advantage specifically for pain during the activities that matter most in daily life — getting up and moving around [3].
Meta-Analysis Confirms Broad Efficacy and Safety
A 2024 meta-analysis pooled data from multiple randomised controlled trials of hydrotherapy for knee osteoarthritis. The pooled results showed significant improvements: mean reductions of 6.5 points for pain and 10.5 points for physical function on validated outcome scales. Critically, no serious adverse events were reported across all included studies [2]. In a field where many treatments carry meaningful risks (gastrointestinal bleeding from NSAIDs, infection risks from injections, surgical complications), that safety profile is worth underlining.
Four Weeks Is Enough to See Results
Tomas-Carus et al. (2017) studied a structured hydrotherapy programme in older women with knee osteoarthritis and found that a 4-week programme significantly decreased pain and improved functional status [4]. That timeline is encouraging. You do not need to commit to months of pool sessions on faith. Four weeks of consistent effort is enough to know whether water therapy is making a difference for you.
The Evidence Extends Beyond Arthritis
A 2023 review in the Journal of Orthopaedic Surgery and Research analysed 32 randomised controlled trials involving over 2,200 participants with chronic musculoskeletal disorders. The conclusion: aquatic exercise produces significant improvements in pain, function, and quality of life across a range of conditions, reinforcing that the benefits are not limited to any single diagnosis [6].
For more on how hydrotherapy addresses joint pain specifically, see our detailed article on the benefits of hydrotherapy for joint pain.
Recommended Water Temperature for Arthritis
Temperature matters. Too cool and you lose the muscle-relaxing and stiffness-reducing benefits. Too hot and you risk fatigue, dizziness, or cardiovascular strain.
The Arthritis Foundation recommends water between 92-100 degrees Fahrenheit (33-38 degrees Celsius) for people with arthritis. Most dedicated hydrotherapy pools fall in the 92-97 degree Fahrenheit range (33-36 degrees Celsius). This is noticeably warmer than standard swimming pools, which are typically kept at 78-82 degrees Fahrenheit (26-28 degrees Celsius).
If you are using a home hot tub, stay at the lower end of the therapy range — around 92-95 degrees Fahrenheit (33-35 degrees Celsius) — and limit sessions to 20-30 minutes. Higher temperatures are more fatiguing and can be problematic if you have cardiovascular issues or take blood pressure medication.
Specific Exercises to Try in Water
These exercises are designed for people with arthritis. All are performed in chest-deep or waist-deep warm water. Start gently. The goal is movement without increased pain the following day.
Water Walking
Walk forward across the pool in chest-deep water at a comfortable pace. Then walk backward. The water resistance strengthens your legs far more than it feels in the moment, while buoyancy protects your knees and hips. Start with 5 minutes and build to 10-15 minutes over several weeks.
Leg Lifts (Front, Side, and Back)
Stand at the pool wall for balance. Lift one leg straight out in front of you, hold for 2-3 seconds, lower slowly. Repeat to the side, and then behind you. Perform 8-10 repetitions in each direction, then switch legs. This mobilises the hip through its full range and strengthens the muscles that stabilise both hip and knee joints.
Arm Circles and Shoulder Rolls
Submerge your arms and extend them to the sides. Make slow, controlled circles — small at first, then gradually larger. The water provides resistance in every direction, strengthening the rotator cuff and shoulder muscles without the jarring impact of land-based overhead exercises. Follow with slow shoulder rolls forward and backward.
Knee Bends
Stand with your feet shoulder-width apart in chest-deep water. Slowly bend your knees, lowering your body as far as is comfortable, then straighten. The water supports a significant portion of your weight, making this far more tolerable than squats on land. Start with partial bends and increase depth over time. Aim for 10-15 repetitions.
Hip Rotations
Stand on one leg (hold the pool wall for balance) and lift the other knee to waist height. Slowly rotate the raised leg in a circular motion, making circles with your knee. Perform 5 circles in each direction, then switch legs. This improves hip joint mobility and is particularly helpful for osteoarthritis of the hip.
Weekly Hydrotherapy Schedule for Arthritis: A 4-Week Progression
This sample programme is based on the session frequencies and durations used in clinical trials showing benefit [2][3][4]. Adjust based on your comfort and your doctor’s guidance.
Week 1: Getting Comfortable
| Day | Activity | Duration |
|---|---|---|
| Monday | Water walking + gentle leg lifts | 20 minutes |
| Wednesday | Water walking + arm circles + knee bends | 20 minutes |
| Friday | Warm-water soak (no structured exercise) | 15-20 minutes |
Focus: Learn the exercises. Find your comfortable range of motion. Do not push into pain.
Week 2: Building Consistency
| Day | Activity | Duration |
|---|---|---|
| Monday | Water walking + leg lifts (all directions) + hip rotations | 25 minutes |
| Wednesday | Water walking + arm circles + shoulder rolls + knee bends | 25 minutes |
| Friday | Full routine at gentle pace | 25 minutes |
Focus: Add all exercises into rotation. Increase water walking to 8-10 minutes per session.
Week 3: Adding Duration
| Day | Activity | Duration |
|---|---|---|
| Monday | Full routine | 30 minutes |
| Wednesday | Full routine | 30 minutes |
| Friday | Full routine | 30 minutes |
Focus: Build to 30-minute sessions. Increase repetitions from 8 to 12. Add sideways walking.
Week 4: Establishing Your Baseline
| Day | Activity | Duration |
|---|---|---|
| Monday | Full routine with increased pace | 30-35 minutes |
| Wednesday | Full routine with increased pace | 30-35 minutes |
| Friday | Full routine + 5 minutes relaxation soak | 35-40 minutes |
Focus: You should be noticing changes by now. Tomas-Carus et al. found measurable improvements at this point [4]. Assess what is working and what needs adjustment. This becomes your ongoing maintenance programme.
After Week 4: Continue 3 sessions per week at the intensity that works for you. Every 2-3 weeks, increase duration or pace slightly. The goal is sustainable, long-term consistency — not rapid progression.
Getting Started: Finding a Hydrotherapy Pool
What to Look For
Search for “hydrotherapy pool,” “warm therapy pool,” or “aquatic therapy” at local hospitals, rehabilitation centres, physiotherapy clinics, and community leisure centres. Dedicated therapy pools are warmer than standard swimming pools (33-36 degrees Celsius versus 27-28 degrees Celsius), and that temperature difference matters for arthritis.
Many NHS trusts and hospital systems offer hydrotherapy programmes specifically for arthritis patients, often through rheumatology or physiotherapy departments. Ask your GP or rheumatologist for a referral.
What to Expect at Your First Session
If attending a guided class, a physiotherapist will typically assess your joint condition, range of motion, and fitness level before your first pool session. They will modify exercises to suit your needs. Group classes usually involve 6-12 people at similar ability levels.
Bring a swimsuit, a towel, and pool shoes (tile floors can be slippery). Arrive early to shower before entering the pool. Expect to feel surprisingly tired afterward — water resistance works your muscles more than you realise. Some mild soreness the next day is normal. If your joint pain significantly worsens after a session, you did too much; scale back next time.
Home Options: Making Hydrotherapy Accessible
Not everyone can get to a therapy pool three times a week. Here is how to bring the benefits home.
Bathtub Routines
A deep, warm bath is not a replacement for pool-based exercise, but it provides genuine therapeutic value. Fill the tub with water at 92-100 degrees Fahrenheit (33-38 degrees Celsius). Soak for 15-20 minutes. While immersed, gently flex and extend your fingers, rotate your wrists, and bend and straighten your knees. This is particularly helpful for morning stiffness or as a wind-down routine before bed.
Adding 1-2 cups of Epsom salt (magnesium sulfate) may provide additional muscle relaxation, though the evidence for transdermal magnesium absorption is limited. What is not in dispute is that the warm-water soak itself helps.
Affordable Equipment
You do not need expensive installations to start. Our guide to affordable hydrotherapy equipment for home use covers practical options, including inflatable hot tubs, deep soaking tubs, and water resistance accessories. If you are considering a more permanent setup, our guide to hydrotherapy tubs compares the options in detail.
Warm Compresses and Contrast Soaks
For hands and feet affected by arthritis, a basin of warm water (100 degrees Fahrenheit / 38 degrees Celsius) provides a localised version of hydrotherapy. Soak affected joints for 10-15 minutes while gently opening and closing your fingers or rotating your ankles. Some people alternate with a cool-water basin (60-70 degrees Fahrenheit / 15-21 degrees Celsius) for a contrast effect that can reduce inflammation.
When to Talk to Your Doctor
Hydrotherapy is safe for most people with arthritis, but consult your doctor or rheumatologist before starting if you have:
- Active, severe joint inflammation — During major RA flares with hot, swollen joints, vigorous pool exercise may aggravate symptoms. Gentle immersion may still be appropriate, but get guidance first.
- Cardiovascular conditions — Uncontrolled high blood pressure, heart failure, or a recent cardiac event. Warm water increases heart rate and dilates blood vessels, which can be problematic.
- Open wounds or active skin infections — Pool water and broken skin do not mix.
- A recent joint replacement or surgery — Timing of pool entry depends on wound healing. Your surgeon will advise.
- Epilepsy or seizure disorders — Water presents a safety risk during seizures.
- Fever or active infection — Wait until you are well.
Red flags during hydrotherapy: If you experience increased joint pain that lasts more than 24 hours after a session, significant new swelling, dizziness, chest pain, or shortness of breath, stop and consult your doctor before continuing.
Frequently Asked Questions
Is hydrotherapy better than regular exercise for arthritis?
For pain relief specifically, the evidence suggests it has an advantage. Hinman et al. (2007) found hydrotherapy superior to land-based exercise for reducing pain before and after walking in knee osteoarthritis [3]. Both forms of exercise improve strength and function, but the buoyancy and warmth of water make the experience less painful during the activity itself. This also means people are more likely to stick with it long-term, which matters enormously for a chronic condition.
How quickly will I notice improvement?
Clinical research shows measurable improvements in as little as 4 weeks with consistent sessions (2-3 times per week) [4]. Some people report feeling better after their very first session — the warm water and gentle movement provide immediate, temporary relief. Lasting changes in strength, flexibility, and baseline pain levels develop over several weeks of regular practice.
Can I do hydrotherapy if I cannot swim?
Yes. Nearly all hydrotherapy exercises are performed while standing in waist-deep or chest-deep water. You do not need to swim, float, or submerge your face. Therapy pools have rails, steps, and ramps for access, and exercises are done while holding the pool edge or using flotation aids. Not being able to swim is the most common concern people raise, and it should not stop you.
Is hydrotherapy safe for elderly people with arthritis?
The evidence strongly supports its safety. The 2024 meta-analysis reported no serious adverse events across all included trials [2], and several of the studies specifically enrolled older adults. The buoyancy of water reduces fall risk compared to land-based exercise, and the warm environment is gentler on aging cardiovascular systems than cold-weather outdoor activity. For elderly people who have become deconditioned due to pain, hydrotherapy is often the safest way to re-introduce regular physical activity.
Will my insurance cover hydrotherapy for arthritis?
Coverage varies by country and plan. In many cases, aquatic physiotherapy prescribed by a doctor for a diagnosed condition such as osteoarthritis or rheumatoid arthritis is covered under physiotherapy benefits. In the UK, NHS hydrotherapy referrals are available through rheumatology and physiotherapy departments. In the US, many insurance plans cover aquatic physical therapy when prescribed by a physician. Spa-style hydrotherapy or self-directed pool use is typically not covered. Contact your insurer to confirm your specific benefits.
This article is for informational purposes only. Always consult your doctor or rheumatologist before starting a new exercise programme, especially if you have active joint inflammation.
Related Reading
- How Hydrotherapy Machines Work: The Physics Behind the Relief
- Warm Water Therapy for Muscle Pain
- Hydrotherapy Pools for Elderly Care
- Choosing the Right Hydrotherapy Equipment
Sources
[1] Al-Qubaeissy, K.Y., et al. (2012). The effectiveness of hydrotherapy in the management of rheumatoid arthritis: a systematic review. Musculoskeletal Care, 11(1), 3-18. PubMed
[2] PMC (2024). The efficacy and safety of hydrotherapy in patients with knee osteoarthritis: a meta-analysis of randomized controlled trials. PMC
[3] Hinman, R.S., Heywood, S.E., & Day, A.R. (2007). Aquatic physical therapy for hip and knee osteoarthritis: Results of a single-blind randomized controlled trial. Physical Therapy, 87(1), 32-43. PubMed
[4] Tomas-Carus, P., et al. (2017). Hydrotherapy improves pain and function in older women with knee osteoarthritis: a randomized controlled trial. PMC
[5] Hall, J., et al. (2007). Physical activity for osteoarthritis management: a randomized controlled clinical trial evaluating hydrotherapy or Tai Chi classes. Arthritis & Rheumatism, 57(3), 407-414. PubMed
[6] Journal of Orthopaedic Surgery and Research (2023). Efficacy of aquatic exercise in chronic musculoskeletal disorders: a systematic review and meta-analysis of 32 randomised controlled trials. JOSR
