Blood in Urine: When Ketamine Use is the Cause

Ketamine use in the UK has reached record levels, with an estimated 299,000 people reporting use in 2024. The rise has been sharpest among young people, and in July 2025, Alder Hey Children’s Hospital opened the UK’s first NHS clinic specifically for under-16s with ketamine bladder damage.

If you’re using ketamine and you’ve noticed blood in your urine, it is a warning sign that the drug is damaging your urinary system. This is not something to just ignore, because the longer you keep using ketamine, the worse that damage gets.

This guide explains why ketamine causes blood in the urine, what’s happening inside your body, and what you can do about it before the damage becomes permanent.

Why does ketamine cause blood in the urine?

When you take ketamine, your body breaks it down into metabolites that are excreted through your urinary system. These breakdown products are toxic to the lining of your bladder, and every time you urinate, the bladder wall is exposed to these chemicals. Repeated exposure causes inflammation, ulceration, and eventually bleeding.

This condition is known as ketamine-induced cystitis or ketamine bladder syndrome. It was first identified in medical literature in 2007, and cases have risen sharply alongside the increase in ketamine use.

The blood you see in your urine comes from the damaged bladder lining. It may appear pink, red, or brown, and you might also notice blood clots. Sometimes the bleeding is microscopic and may only show up on a urine test.

The severity of the damage depends on how much you use ketamine, how often, and for how long. It also varies a lot from person to person, with some people developing symptoms after just months of use, and others potentially using ketamine for years before problems appear. However, there is no safe threshold, so if you’re using ketamine regularly, you’re putting your bladder at risk.

How does ketamine bladder syndrome progress?

Ketamine bladder syndrome develops in stages, so the earlier you stop using, the better your chances of recovery.

In the early stages, the bladder lining becomes inflamed and irritated. You may need to urinate more often, or feel it burning when you do. At this point, the damage is usually reversible if you stop using ketamine.

As ketamine use continues, however, the inflammation worsens. Ulcers form on the bladder wall, and the tissue begins to thicken and scar. The bladder starts to lose its elasticity, and as a result, its ability to stretch and hold urine. A healthy bladder can hold around 400 to 500 millilitres. In severe ketamine bladder syndrome, this can shrink to under 50 millilitres. That’s why some heavy ketamine users need to urinate every few minutes, day and night.

In advanced cases, the scarring becomes permanent. This is called fibrosis, and it cannot be reversed. The damage can also spread beyond the bladder to the ureters (the tubes connecting your kidneys to your bladder) and the kidneys themselves. When urine can’t drain properly, it backs up into the kidneys, causing a condition called hydronephrosis. Left untreated, this can lead to kidney failure.

In the most severe cases, the bladder becomes so damaged that it has to be surgically removed. This means living with a urostomy bag for the rest of your life. These cases are not common, but they are increasing, and they are entirely preventable.

What are some other warning signs to watch for?

Blood in your urine is a serious symptom, but it’s often not the first sign of ketamine bladder damage. Other symptoms to be aware of include:

• Needing to urinate very frequently
• A sudden, intense urge to urinate that’s difficult to control
• Pain or burning during urination
• Pelvic pain or cramping in your lower abdomen
• Incontinence
• Passing blood clots
• Pain during sex

These symptoms are sometimes called “k-cramps” among ketamine users. They’re often dismissed or attributed to other causes, but if you’re using ketamine and experiencing any of them, your bladder is telling you something is wrong.

When to seek emergency help?

Some symptoms require urgent medical attention. Go to the hospital or call 999 if you experience:

• Heavy bleeding or large blood clots in your urine
• Complete inability to urinate despite feeling the need to (urinary retention)
• Severe pain in your back or sides (a common sign of kidney involvement)
• Fever alongside urinary symptoms (a possible symptom of infection)

These are signs that the damage may have progressed to a dangerous level or that a complication has developed. Ketamine-related deaths have increased twentyfold since 2014, often involving complications or mixing ketamine with other substances.

What happens when you see a doctor?

If you’re experiencing urinary symptoms related to ketamine use, you will likely be asked to provide a urine sample, which will be tested for blood, infection, and protein. You may also undergo blood tests to check your kidney function, and an ultrasound or CT scan to show the thickness of your bladder wall, any scarring, and whether there’s damage to your kidneys or ureters.

In some cases, you may be referred for a cystoscopy, which is a procedure where a small camera is inserted into your bladder to assess the damage directly.

Treatment depends on how severe the damage is. For early-stage cases, anti-inflammatory medications and pain management may help while your bladder heals. Some patients receive bladder instillations, which are medications delivered directly into the bladder. For advanced cases, surgical options may be necessary, including bladder augmentation or, in extreme cases, removal.

The most important thing you can do is be honest with your doctor about your ketamine use. They cannot help you properly if they don’t know what is causing the damage. Remember that medical staff are not there to judge you. They have seen it all before, and their only concern is your health.

Why stopping ketamine is essential

No medical treatment will work if you keep using ketamine, as the bladder can’t heal while it’s still being exposed to the chemicals causing the damage.

The good news is that early-stage damage often reverses after a few weeks or months of stopping. The bladder lining can regenerate, inflammation subsides, and other symptoms should improve relatively quickly. Many people who stop at this stage go on to make a full recovery.

But late-stage damage, like fibrosis, a shrunken bladder, and kidney involvement, is usually permanent. Once the first symptoms have appeared, continuing to use ketamine can dramatically accelerate this damage.

But that doesn’t mean you should accept that nothing can be done. If you have only just started noticing, you’re in a window where stopping now could mean the difference between full recovery and lifelong consequences.

How to get help for ketamine addiction

Stopping ketamine isn’t always straightforward, especially if it’s become a way of coping with stress, emotional pain, or mental health difficulties. Ketamine can be both psychologically and physically addictive, and the number of people entering treatment for ketamine addiction increased from 426 in 2014-15 to over 5,300 in 2024-25.

Ketamine addiction treatment options include local drug and alcohol services, which are free through the NHS and can offer outpatient counselling and local support groups. These may be enough for people with severe dependencies, but if you are showing signs of bladder damage, you may already be past this point.

For people with a more severe addiction to ketamine, and those who haven’t succeeded with outpatient treatment, residential ketamine rehab provides intensive, round-the-clock support. It may begin with medical ketamine detox, and then a programme of therapy, and ongoing aftercare planning and support.

If you’re unsure where to start, EATA can help. Contact us for free, confidential advice about ketamine addiction treatment options and what might work for your situation. We can talk you through what’s available and help you take the next step, whether that’s for yourself or someone you care about.