What Systems Does Ketamine Affect? Understanding the Wider Impact of Ketamine Use

Oct 15

8 min read

Ketamine is often associated with bladder damage, but its effects can extend much further, affecting physical health, memory, emotions, sleep and everyday functioning.

Ketamine is a dissociative anaesthetic used in medicine, but repeated non-medical use, particularly at higher doses, can be associated with a wide range of health problems.

Some difficulties develop gradually, while others can emerge relatively quickly. One person may develop painful bladder symptoms, another may struggle with memory or concentration, while someone else may experience increasing anxiety, abdominal pain or difficulty controlling their use.

These problems do not necessarily occur together, and their severity can vary considerably.

Understanding the wider effects of ketamine matters because harm can develop in several areas of someone's life, even when they do not consider themselves dependent on the drug.

The KASPR (Ketamine Assessment, Screening & Progression Risk) framework takes a whole-person approach, recognising that physical, psychological and behavioural difficulties can overlap and influence one another.

The main areas affected by ketamine

1. Bladder, kidneys and urinary functioning

Bladder problems are among the most widely recognised consequences of repeated ketamine use.

Ketamine and substances produced when the body breaks it down can contribute to inflammation and damage within the urinary system. Over time, the bladder may become increasingly sensitive, painful and less able to hold urine comfortably.

Warning signs can include:

Needing to urinate much more frequently, sometimes every few minutes.
Waking repeatedly during the night to use the toilet.
Experiencing sudden urgency, with little warning.
Burning, stinging or pain when urinating.
Pain or pressure in the lower abdomen.
Leaking urine or struggling to reach the toilet in time.
Blood appearing in the urine.

These difficulties can significantly disrupt everyday life. Someone may start planning journeys around toilet availability, avoiding social activities or finding it difficult to remain at work. Repeatedly waking during the night can also leave people exhausted.

In more severe cases, the bladder can become scarred and lose its ability to stretch. Problems can extend beyond the bladder, affecting the tubes carrying urine from the kidneys and sometimes preventing urine from draining normally.

This can result in swollen kidneys, repeated infections and potentially permanent damage to kidney function. Importantly, kidney problems do not always produce obvious symptoms in their early stages.

In a UK survey, 26.6% of respondents who had used ketamine in the previous year reported urinary symptoms (Winstock et al., 2012). This was a self-selected sample and should not be interpreted as the prevalence among all people who use ketamine.

Some urinary symptoms improve after ketamine use stops, particularly when problems are identified early. However, advanced bladder and kidney damage may not fully recover (Belal et al., 2024).

2. Abdominal pain and digestive functioning

Repeated ketamine use can also be associated with severe abdominal pain, sometimes described as K-cramps.

These episodes can be particularly distressing and may occur alongside other digestive difficulties.

People may experience:

Sudden, gripping or cramping abdominal pain.
Repeated episodes of severe stomach discomfort.
Nausea or vomiting.
Reduced appetite or difficulty eating normally.
Pain that disrupts sleep or prevents everyday activities.

For some people, the pain is intense enough to interrupt work, education or social life.

A difficult pattern can develop when someone uses more ketamine to obtain temporary relief from the pain. Although ketamine can reduce the immediate experience of discomfort, continued exposure may contribute to further harm.

The causes of ketamine-associated abdominal pain are not completely understood. Some episodes may involve the stomach or digestive system, while others may reflect problems affecting the liver, bile ducts or urinary tract.

Persistent or severe abdominal pain therefore needs proper medical assessment rather than simply being accepted as an unavoidable consequence of ketamine use (ACMD, 2026).

3. Memory, concentration and thinking

Ketamine can interfere with the brain's ability to process, retain and organise information.

Research involving people who use ketamine frequently has identified difficulties with memory, attention, learning and decision-making (Morgan et al., 2010).

These changes may not always be obvious at first.

Commonly reported difficulties include:

Forgetting conversations, appointments or arrangements.
Struggling to remember recently learned information.
Losing concentration during conversations or tasks.
Finding it difficult to follow instructions.
Taking longer to process information.
Struggling with planning, organisation or decision-making.
Feeling mentally slower or less alert than previously.

These changes can have consequences beyond the immediate effects of ketamine.

Someone may begin falling behind at work, experiencing difficulties with education or relying increasingly on other people to manage ordinary responsibilities.

Memory difficulties may also create tension in relationships, particularly when someone repeatedly forgets arrangements or struggles to follow through with plans.

A systematic review identified differences in brain structure and connections between brain regions among people with prolonged, heavy ketamine use (Strous et al., 2022).

However, the extent to which cognitive difficulties improve after stopping ketamine varies, and more long-term research is needed.

4. Mood, emotions and psychological wellbeing

Ketamine can produce temporary feelings of detachment from difficult emotions, thoughts or experiences. For some people, this forms part of its attraction.

However, frequent non-medical use can also be associated with problems affecting emotional wellbeing.

These may include:

Increased anxiety or panic.
Persistent low mood.
Irritability or rapid changes in mood.
Feeling emotionally numb or disconnected.
Losing interest in previously enjoyable activities.
Difficulty managing stress or everyday pressures.
Feeling detached from one's body, surroundings or sense of identity.
Suspiciousness, unusual perceptions or psychotic-like experiences.

The experience of dissociation is particularly relevant to ketamine. It can involve feeling separated from the body, disconnected from emotions or as though the surrounding world is unreal.

Although these experiences may be sought during intoxication, unwanted or persistent feelings of disconnection can become distressing.

Emotional difficulties can affect relationships, confidence, employment and social functioning. Someone may become increasingly withdrawn, struggle to manage ordinary demands or find that ketamine becomes one of their main ways of coping.

The relationship between ketamine and mental health is complex. Psychological difficulties may exist before ketamine use begins, contribute to continued use or worsen alongside it (Morgan et al., 2010).

It is also important to distinguish these risks from the carefully controlled medical use of ketamine and esketamine for particular conditions.

5. Sleep, tiredness and everyday functioning

Sleep problems are an important but sometimes overlooked part of ketamine-related harm.

People may experience repeated sleep disruption because of urinary symptoms, abdominal pain, emotional distress or irregular patterns of substance use.

Everyday consequences can include:

Waking repeatedly throughout the night.
Feeling exhausted during the day.
Struggling to get up in the morning.
Difficulty concentrating or staying motivated.
Increased irritability and emotional sensitivity.
Reduced ability to manage work, study or family responsibilities.

These difficulties can reinforce one another.

For example, someone experiencing bladder pain may wake repeatedly during the night. The resulting exhaustion can make concentration more difficult, increase irritability and reduce their ability to manage everyday pressures.

Over time, the combined effect of pain, poor sleep and emotional distress can substantially reduce quality of life.

Not all these problems result directly from ketamine's effects on sleep. Many arise because other ketamine-related difficulties interfere with rest and everyday functioning.

6. Urges, patterns of use and loss of control

Ketamine can also affect behaviour, motivation and the ability to regulate substance use.

Some people develop increasingly frequent patterns of use, while others find it difficult to stop despite recognising harmful consequences.

Signs of a developing problem may include:

Using ketamine more frequently than originally intended.
Needing larger amounts to experience the desired effects.
Spending increasing amounts of time thinking about or obtaining ketamine.
Repeatedly trying to reduce use without sustaining the change.
Continuing to use despite pain, urinary symptoms or other difficulties.
Spending money intended for other responsibilities on ketamine.
Gradually withdrawing from activities that do not involve ketamine.

For some people, the reasons for using ketamine may also change.

What begins as occasional use for enjoyment or social experiences can develop into a pattern in which ketamine is increasingly used to manage anxiety, boredom, distress or unwanted feelings.

This may make changing established patterns of use more difficult, particularly when ketamine has become closely linked with daily routines and ways of coping.

However, not everyone experiencing ketamine-related harm develops dependence. Serious physical complications can occur without all the features traditionally associated with addiction (ACMD, 2026).

This is one reason why understanding ketamine-related difficulties requires attention to more than frequency of use or dependence alone.

Other identified and emerging effects

Alongside these main areas, research has identified several additional health concerns. Some are well recognised, while others remain at an earlier stage of investigation.

Sexual functioning and intimacy

Ketamine-related urinary problems may also affect sexual health.

People can experience pain during sex, erectile difficulties, painful ejaculation, reduced sexual activity or anxiety about intimacy.

A study published in 2026 involving 123 men with established ketamine-related urinary problems found high levels of sexual difficulties, including erectile and ejaculation problems (Leerssen et al., 2026).

The findings relate to people already experiencing urinary damage and should not be generalised to everyone using ketamine. Nevertheless, they highlight an important and often overlooked consequence for intimate relationships and quality of life.

Liver and bile ducts

Repeated ketamine exposure can cause problems affecting the liver and the tubes carrying bile into the digestive system.

Some people develop abnormal liver blood tests without obvious symptoms. Others may experience upper abdominal pain, nausea, tiredness, dark urine or yellowing of the skin and eyes.

More serious complications can involve inflammation or narrowing of the bile ducts and may require specialist treatment (ACMD, 2026).

Heart and circulation

Ketamine can temporarily increase heart rate and blood pressure.

During intoxication, some people experience a racing heart, palpitations or feelings of physical agitation. These effects may be especially concerning for people with existing cardiovascular problems.

The longer-term cardiovascular consequences of repeated non-medical ketamine use are less well established.

Nasal passages

Repeatedly snorting ketamine can irritate and damage the inside of the nose.

This may lead to soreness, congestion, nosebleeds or persistent nasal discomfort. These problems relate partly to repeated exposure to powdered substances through the nose, rather than being unique to ketamine.

Hormonal and metabolic functioning

Emerging research has also identified possible changes in leptin, a hormone involved in appetite and energy regulation.

A 2024 study found lower leptin levels among women with ketamine use disorder compared with women without the disorder. The same difference was not found among men (Huang et al., 2024).

These findings are preliminary. It is not yet clear whether ketamine directly causes these changes or what they mean for long-term health.

They nevertheless suggest that the potential effects of repeated ketamine use may extend into areas that have received relatively little research attention.

Why understanding the wider effects matters

Ketamine-related difficulties rarely exist entirely in isolation.

Bladder pain may interfere with sleep. Poor sleep can affect concentration, memory and emotional wellbeing. Cognitive difficulties may disrupt work or relationships. Emotional distress may then become another reason someone continues using ketamine.

These overlapping difficulties can make it harder to recognise the full extent of someone's problems when individual symptoms are considered separately.

The KASPR framework was developed to support a more comprehensive understanding of ketamine-related harm, recognising that physical health, psychological wellbeing and patterns of use can interact and change over time.

The central message is that ketamine-related harm is not limited to bladder damage or dependence.

Recognising emerging difficulties across different areas of functioning can help people seek support earlier and enable practitioners to respond more appropriately.

Not everyone who uses ketamine will experience these complications. However, new or persistent symptoms should not be ignored simply because someone is young, uses ketamine intermittently or does not consider themselves dependent.

Medical assessment is important for persistent urinary problems, abdominal pain, cognitive changes or other concerning symptoms. Severe abdominal pain, inability to pass urine, significant bleeding or jaundice requires urgent medical attention.

References

Advisory Council on the Misuse of Drugs (ACMD) (2026) Ketamine: an updated review of use and harms. London: Home Office. Available at: https://www.gov.uk/government/publications/ketamine-an-updated-review-of-use-and-harms (Accessed: 15 October 2026).

Belal, M., Downey, A., Doherty, R., Ali, A., Hashim, H., Kozan, A., Kujawa, M., Pakzad, M., Rashid, T., Osman, N., Sahai, A. and Biers, S. (2024) ‘British Association of Urological Surgeons Consensus statements on the management of ketamine uropathy’, BJU International, 134(2), pp. 148–154. https://doi.org/10.1111/bju.16404.

Huang, M.-C., Chiang, L.-J., Chien, W.-H., Liu, T.-H., Chen, C.-H. and Liu, Y.-L. (2024) ‘Plasma leptin levels are lower in females, but not males, with ketamine use disorder’, The American Journal of Drug and Alcohol Abuse, 50(5), pp. 659–669. https://doi.org/10.1080/00952990.2024.2394963.

Leerssen, E.C.M., van der Sanden, W.M.H., de Kemp, V.F., Schipper, R.A., Wyndaele, M.I.A. and Kort, L.M.O. (2026) ‘Ketamine abuse also affects sexual health’, Sexual Medicine, 14(5), article qfag049. https://doi.org/10.1093/sexmed/qfag049.

Morgan, C.J.A., Muetzelfeldt, L. and Curran, H.V. (2010) ‘Consequences of chronic ketamine self-administration upon neurocognitive function and psychological wellbeing: a 1-year longitudinal study’, Addiction, 105(1), pp. 121–133. https://doi.org/10.1111/j.1360-0443.2009.02761.x.

Strous, J.F.M., Weeland, C.J., van der Draai, F.A., Daams, J.G., Denys, D., Lok, A., Schoevers, R.A. and Figee, M. (2022) ‘Brain changes associated with long-term ketamine abuse, a systematic review’, Frontiers in Neuroanatomy, 16, article 795231. https://doi.org/10.3389/fnana.2022.795231.

Winstock, A.R., Mitcheson, L., Gillatt, D.A. and Cottrell, A.M. (2012) ‘The prevalence and natural history of urinary symptoms among recreational ketamine users’, BJU International, 110(11), pp. 1762–1766. https://doi.org/10.1111/j.1464-410X.2012.11028.x.