Interstitial cystitis (IC) and overactive bladder (OAB) are two distinct but related conditions that affect the bladder and can significantly affect quality of life.

IC is also referred to as bladder pain syndrome (IC/BPS).

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While they are distinct disorders, IC/BPS and OAB share similar symptoms, such as urgency, frequency, and pelvic pain, which can make it difficult to distinguish between the two.

Interstitial cystitis/bladder pain syndrome

IC/BPS is a chronic condition that involves bladder pain and a feeling of pressure in the bladder area, among other symptoms.

This condition is part of a spectrum of disorders that cause pelvic pain and urinary symptoms that significantly affect quality of life.

IC/BPS is often mistaken for a urinary tract infection (UTI), but it does not involve a bacterial infection and does not typically respond to antibiotics.

Overactive bladder

OAB is a condition that involves a group of urinary symptoms. These symptoms include a sudden, uncontrollable urge to urinate, frequent urination, and, in some cases, involuntary loss of urine (urge incontinence).

OAB is a common condition that can significantly affect a person’s quality of life, leading to disruptions in daily activities, sleep, and social interactions.

Both IC/BPS and OAB involve symptoms like frequent urination and a strong urge to urinate.

Interstitial cystitis/bladder pain syndrome

Symptoms of IC/BPS typically include the following:

  • Chronic pelvic pain: Persistent pain or pressure in the bladder and pelvic region, often worsening as the bladder fills.
  • Frequent urination: Needing to urinate more than the average 7 times per day, sometimes up to 60 times a day in severe cases.
  • Urgency: A strong, sudden need to urinate, often accompanied by discomfort. Incontinence may also occur.
  • Pain during sex: Many people with IC/BPS experience pain during sexual intercourse.

Overactive bladder

Symptoms of OAB usually include:

  • Urgency: A sudden, strong need to urinate that is difficult to control.
  • Frequency: Urinating more than 8 times in 24 hours.
  • Nocturia: Waking up more than once during the night to urinate.
  • Urge incontinence: Unintentional loss of urine immediately after an urgent need to urinate.

The causes of IC/BPS and OAB differ.

Interstitial cystitis/bladder pain syndrome

The exact cause of interstitial cystitis is not well understood. However, researchers believe it to be related to several factors. These include a defect in the bladder’s protective lining (urothelium), which may allow irritating substances in urine to penetrate and inflame the bladder wall.

Some researchers suggest that IC might be related to an autoimmune response, where the body’s immune system mistakenly attacks healthy cells in the bladder.

Other potential causes include:

  • the presence of an inflammatory cell, which causes an allergic reaction, resulting in symptoms of IC/BPS
  • change in the nerves that cause bladder sensations
  • injury to the bladder

Overactive bladder

The specific cause of OAB is unknown. The symptoms of OAB develop due to the overactivity of the detrusor muscle, which controls bladder contractions. In OAB, this muscle contracts involuntarily, even when the bladder is not full.

Some risk factors can include:

Conditions like multiple sclerosis, Parkinson’s disease, and stroke can affect the nerves that control the bladder, leading to OAB symptoms.

To diagnose either IC/BPS or OAB, doctors typically follow the same steps. These include the following:

  • Medical history and symptom review: Doctors will consider the person’s symptoms and medical history and perform a physical exam.
  • Bladder diaries: People may need to keep a record of their urination patterns, fluid intake, and symptoms.
  • Urinalysis and cultures: This can rule out infections.

Cystoscopy is a procedure that allows doctors to view the inside of the bladder. They often perform this procedure to diagnose IC/BPS.

Urodynamic testing measures the bladder’s ability to store and release urine, which is useful for diagnosing OAB.

Initially, doctors may advise people to try conservative treatments.

Interstitial cystitis/bladder pain syndrome

People with IC/BPS often start with dietary changes. These include avoiding foods and drinks that irritate the bladder, such as caffeine, alcohol, spicy foods, and acidic fruits.

Bladder training techniques can help people gradually increase the time between urinations. Stress management strategies can address stress, which can worsen symptoms. Examples include:

  • relaxation techniques
  • medication
  • counseling

Overactive bladder

For OAB, treatment typically begins with behavioral therapies that aim to improve bladder control and reduce symptoms.

Bladder training programs help people gradually increase the intervals between urination. Scheduled toileting (scheduled voiding) encourages regular bathroom trips to reduce urgency.

Pelvic floor exercises, such as Kegels, strengthen the pelvic floor muscles, improve bladder control, and reduce incontinence.

If home remedies are unsuccessful, people may consider medical treatment.

Interstitial cystitis/bladder pain syndrome

Treatment for IC may include:

  • oral medications
  • direct bladder treatments
  • physical therapy
  • hydrodistention
  • nerve stimulation techniques
  • surgery

Overactive bladder

Treatment for OAB may include:

  • oral medications, such as antimuscarinics and beta-3 adrenoceptor agonists
  • Botox injections into the bladder
  • neuromodulation techniques
  • percutaneous tibial nerve stimulation

Can inflammation cause overactive bladder (OAB)?

Yes, inflammation in the bladder or surrounding tissues can irritate the bladder muscle. This leads to symptoms of OAB, including urgency, frequency, and sometimes urge incontinence.

What does a flare-up of interstitial cystitis feel like?

A flare-up of IC/BPS typically feels like increased pelvic or bladder pain, increased urgency, and more frequent urination.

People may describe the pain as burning, sharp, or pressure-like, and symptoms can intensify with bladder filling and be temporarily relieved after urination.

Both IC/BPS and OAB are chronic conditions that may require long-term management. They share similar symptoms, such as pelvic pain, urinary urgency, and urinary frequency.

The effect on quality of life can be significant, making early diagnosis and comprehensive treatment important. Treatment can significantly ease symptoms, but complete relief may not be possible for everyone.