Bladder pain syndrome (interstitial cystitis)

This is long-standing pelvic pain arising from the bladder, together with frequent and urgent needs to pass urine, in the absence of any infection in the urine. The two names refer to the same condition: "interstitial cystitis" comes from a description of changes in the bladder wall, while "bladder pain syndrome" fits the reality better, because in most people no inflammation is found at all when they are examined. The diagnosis is not made by a single test but by ruling everything else out, and reaching it often takes years — which is the hardest part of the illness for those who live with it.

What it feels like

The picture is made of pain plus disturbed voiding, and in different people one or the other dominates.

• pain or pressure low in the abdomen, above the pubic bone; in women it may spread to the vagina and perineum, in men to the scrotum, the tip of the penis and the area between scrotum and back passage;
• pain that builds as the bladder fills and settles immediately after passing urine — the most recognisable feature of all;
• sudden urges that are hard to hold;
• passing urine more often than usual, sometimes in small amounts many times a day;
• getting up at night, so that sleep is broken;
• pain during or after sex, in women often the next day as well.

Blood in the urine, difficulty starting the stream and leaking are not features of this syndrome. If they are present, they are a reason to look for another cause rather than to fold them into the diagnosis.

Who gets it and how it behaves

It occurs at any age but far more often in women, and usually after thirty. In men the same picture frequently travels under the label of "chronic prostatitis" and is treated with antibiotics for years without result.

The course comes in waves: weeks or months of calm alternate with flares. The trigger is usually certain foods and drinks, a period, stress, lack of sleep, long spells of sitting, tight clothing or sex. It is precisely this waviness that makes it hard to tell whether a treatment worked or a flare simply ended, which is why the effect is judged after a couple of months rather than after a week.

The syndrome often keeps company with conditions in which the nervous system amplifies the perception of pain: fibromyalgia, irritable bowel syndrome, myalgic encephalomyelitis (chronic fatigue syndrome), migraine. This is neither coincidence nor "nerves": a shared mechanism genuinely exists, and knowing about it changes the approach to treatment.

Why it happens

No single cause has been found, and it is more honest to speak of several explanations that complement one another.

• Damage to the protective layer. The bladder is lined on the inside by a layer that keeps urine away from living tissue. If it becomes leaky, components of the urine irritate the wall and the nerve endings beneath it.
• Rewiring of the nervous system. The nerves leaving the bladder and the brain areas that process their signals become oversensitive, so that even modest filling registers as pain.
• The pelvic floor muscles. They tighten in response to pain, the tightening itself hurts, and the circle closes.
• An immune and inflammatory reaction in the bladder wall, with mast cells among the players.
• Hidden infection. In some people a persistent urinary infection lies behind the picture and is missed by routine urine culture.

The form with so-called Hunner lesions deserves a separate mention: patches of ulcerated lining that can be seen when the bladder is inspected from within. They are found in a minority, but an important minority, because that form runs a harder course and in exchange has a targeted treatment that does not exist for the rest.

What has to be ruled out first

The same complaints are produced by conditions that must not be missed. That is why the diagnosis is not handed over straight away, and the delay is justified.

• Bladder cancer. The main warning sign is visible blood in the urine, especially in smokers and older people.
• Urinary tract infection, including recurrent ones and those that are hard to detect.
• Stones in the bladder or the lower ureter.
• Endometriosis, in women whose pain tracks the menstrual cycle.
• Sexually transmitted infections and pelvic inflammatory disease.
• Gynaecological and bowel causes of pelvic pain.

See a doctor the same day if the urine turns pink, red or the colour of strong tea; if pain low in the abdomen or in the loin comes with fever and shivering; if you feel the urge but cannot pass urine at all, because retention needs immediate attention. An ambulance — in Spain, Italy, Portugal, Poland and Ukraine reached on the single European number 112 — is for severe illness with high fever, confusion and marked weakness, which is how an infection that has spread beyond the urinary tract shows itself. A flare of pain, however unbearable, is not an ambulance matter: what it needs is an appointment.

How the diagnosis is reached

There is no confirmatory test. The doctor works from the character of the complaints and how long they have lasted, and investigations serve to strip away other causes. What tends to be used:

• urine testing and culture and, where needed, extended studies for hidden infection;
• a bladder diary: a few days of recording how much you drink, how much you pass and when, and how bad the pain is. It is a simple and surprisingly informative document, worth taking to the appointment;
• ultrasound of bladder and kidneys, including the volume left behind after voiding;
• cystoscopy, looking inside the bladder with a fine camera, mainly to exclude a tumour and to search for Hunner lesions;
• urodynamic studies where the picture is unclear;
• a gynaecological examination and swabs in women, assessment of the prostate in men;
• CT or MRI scanning in selected cases.

Not everyone needs the full set. Ask what each test is for and what would change in your treatment depending on the result: it is a sensible question and a good doctor answers it without irritation.

What is in your own hands

Everyday measures do not replace treatment, but in some people they noticeably reduce how often flares come, and they are usually the starting point.

• Find your own trigger foods. There is no universal banned list. The usual suspects are coffee and tea, alcohol (wine and beer especially), fizzy drinks, citrus fruit and juices, tomatoes, spicy food, chocolate and sweeteners. Do not cut everything at once: drop two or three for a couple of weeks, bring them back one at a time and watch what happens. Otherwise the diet narrows to four dishes with nothing gained.
• Drink enough, spread through the day. Cutting fluids sharply is a common mistake: concentrated urine irritates more. Steady drinking across the day is best tolerated.
• Stop smoking. Substances from tobacco smoke leave the body in the urine and irritate the bladder wall; smoking is also the leading risk factor for bladder cancer.
• Work on stress and sleep. Pain feeds anxiety and anxiety feeds pain. Breathing exercises, a warm bath, gentle activity and proper sleep are not filler here but part of the treatment.
• Neither hold on to the limit nor go pre-emptively. Both make things worse: the bladder either overstretches or grows used to tiny volumes. A doctor may suggest gradually retraining the intervals.
• Treat the pelvic floor gently. The strengthening exercises recommended for leaking can do harm here: the muscles are already in spasm and need to release rather than gain power. A physiotherapist trained in pelvic floor work handles this.

What a specialist can offer

If the complaints do not settle, you need a urologist, and women a urologist or urogynaecologist who works with pelvic pain. There is no single treatment that suits everybody; the evidence behind most of the options is weak, and the choice is made by trial, from simple to complex.

Tablets and capsules. Ordinary painkillers — paracetamol and non-steroidal anti-inflammatories — do little for chronic pelvic pain and are not suitable for continuous use. More is gained from drugs that act on nerve-type pain: low-dose tricyclic antidepressants and gabapentinoids. The dose is built up gradually and the effect judged after some weeks. Where urgency dominates, drugs that relax the bladder muscle are used: anticholinergics and beta-3 receptor agonists. Pentosan polysulfate sodium stands apart, intended to repair the protective layer: it acts slowly, does not suit everyone, and on long-term use requires regular eye checks, since changes in the retina have been described. It is worth asking about that if it is offered to you.

Bladder instillations. Through a fine catheter a solution is put into the bladder and left there for a while. Local anaesthetics are used, as are hyaluronic acid or chondroitin sulphate to repair the lining, and mixtures containing steroids and heparin. The sessions are given in courses.

Non-drug help. Pelvic floor physiotherapy aimed at relaxation, psychological support and learning to manage chronic pain, transcutaneous electrical nerve stimulation, acupuncture. For severe pain, referral to a specialist pain service is appropriate — not because the pain is "in the head", but because they know how to build a long-term plan.

Procedures and surgery. Hunner lesions are cauterised or cut away during cystoscopy, and this gives the most reliable relief on the whole list, though it may need repeating in time. Stretching the bladder with fluid is combined with the inspection; its effect is short-lived. Botulinum toxin injections into the bladder wall reduce urgency and pain for some months but occasionally make emptying difficult, in which case a catheter is needed for a while. Neuromodulation, an implanted device that stimulates the pelvic nerves, comes in when everything else has been exhausted. Removing the bladder is discussed in exceptional cases and for very few people: it is an irreversible operation requiring a new route for the urine, and it does not guarantee that the pain will go.

Online consultation

At an online appointment the doctor will take your complaints apart: exactly where it hurts, whether the pain follows bladder filling and eases on passing urine, how many times a day you go, what sets off the flares, and how all of it lands on sleep, work and your relationship. They will check separately for the signs that call for a face-to-face assessment — blood in the urine, fever, a change in the usual pattern — and review what has already been done: which tests were taken, which courses of antibiotics you have had and with what result. By the end it will be clear which investigations are missing, what can be started now and which specialist is worth seeing. Often the most valuable thing about that appointment is the explanation of why the tests come back clean while the pain is entirely real.

This material is for information only and does not replace medical advice.