Ankylosing spondylitis, now often called axial spondyloarthritis, causes inflammatory back pain and stiffness that behaves opposite to ordinary back pain. Rest makes it worse.
Movement makes it better.
That pattern is why heat in the morning suits it so well, and why exercise is the treatment rather than the optional extra.
Inflammatory vs mechanical back pain
| Inflammatory (AS pattern) | Mechanical (ordinary back pain) |
|---|---|
| Started before about age 45, often gradually | Any age, often after a specific event |
| Morning stiffness over 30 minutes | Brief stiffness, eases quickly |
| Wakes you in the second half of the night | Usually eases when lying still |
| Better with exercise | Often worse with exercise |
| Worse with rest | Better with rest |
| Present more than three months | Usually settles in weeks |
The right-hand column is covered in when a heating pad helps back pain and back pain in the first two weeks.
If the left column describes you and nobody has investigated it, ask your doctor about a rheumatology referral. Diagnosis is commonly delayed by years, and treatment works better started early. The same early-morning, better-with-movement pattern shows up in rheumatoid arthritis.
A morning routine
- Heat, 15–20 minutes across the lower back and pelvis, cover on, low setting. A long warm shower works just as well and covers more ground; see moist heat vs dry heat.
- Then move, while you’re warm. This is the part that counts. See “my physio said use heat” — but how, exactly?
- Keep moving through the day. Long periods at a desk or in a car bring the stiffness back. See sitting back pain and back pain after a long flight.
A pad long enough to cross the lower back and pelvis is the practical size: heat pad size guide.
The movements that matter
AS tends to pull the spine into a flexed, stooped position over years. Exercises that work against that are the priority:
- Extension. Lying on your front propped on elbows, or standing backbends. Work the spine into extension daily.
- Rotation. Seated or lying trunk twists, both directions.
- Chest expansion. Deep breathing exercises. AS can stiffen the rib joints and reduce how far the chest expands. On rib-area pain generally, see rib and chest wall strain.
- Posture check. Standing with heels, bottom and back of the head against a wall, held for 30 seconds.
- Something cardiovascular you’ll keep doing. Swimming suits many people; see swimming neck and shoulder pain if technique starts to bite.
A physiotherapist who knows AS is worth seeing to set a programme. Consistency over years matters more than intensity in any one week. On the harder days, a written flare plan keeps you from losing a week.
Where heat fits, honestly
Heat makes the first hour of the day bearable so you can do your exercises. It doesn’t affect the inflammation or the long-term course of the condition. Medication does that, and for many people it makes a substantial difference.
If you’re relying on heat and painkillers alone with no rheumatology review, that’s the gap to close.
See a doctor if…
- You recognise the inflammatory pattern and have never been assessed
- You develop a red, painful eye with light sensitivity or blurred vision. Uveitis is common in AS and needs same-day treatment.
- You have new bowel symptoms, a rash, or heel pain, which can be linked. See heel pain and Achilles stiffness.
- Your back pain changes character, or follows a fall. Spinal fractures are more likely in a stiffened spine and need urgent assessment.
- You have new numbness, weakness, or bladder or bowel changes. Go to A&E.
Before using a pad daily, check who should not use a heating pad.
The heat pad we use
We’ve supplied the Bremed BD7800 since 2010. It holds a steady temperature, covers a whole lower back and has a machine-washable cotton cover. Physiotherapy clinics in Singapore use it with their patients.
Clinically reviewed by: Nigel Chua (Hand Occupational Therapist) & Louise Yow (Physiotherapist). This article is general information, not a diagnosis. electricheatpad.com sells electric heat pads.
