This article provides general information and is not intended to diagnose the cause of erectile dysfunction or recommend a particular treatment. If erection difficulties keep happening, speak to your GP or another appropriately qualified healthcare professional for individual assessment.
If you are wondering what causes erectile dysfunction, there is rarely one universal answer. Erections depend on healthy blood flow, functioning nerves, appropriate hormone levels and sexual arousal. A problem affecting any part of that system can make it difficult to get or maintain an erection.
Physical conditions such as cardiovascular disease and diabetes can contribute, but stress, anxiety, hormonal changes, medicines and lifestyle factors may also play a part. In practice, more than one factor may be involved. Persistent erectile dysfunction therefore deserves proper assessment rather than assumptions about what is causing it.
How Does an Erection Normally Happen?
An erection involves several body systems working together.
Sexual stimulation triggers signals from the brain and nerves that help relax smooth muscle within the penis. This allows more blood to enter the erectile tissue. As the penis fills, the veins carrying blood away are compressed, helping the erection remain firm.
For this process to work normally, you generally need:
- sufficient blood flow
- functioning nerves
- appropriate hormone levels
- sexual stimulation and desire
- normal communication between the brain, nervous system and penis
A problem in any of these areas can contribute to erectile dysfunction. This is why ED can have vascular, neurological, hormonal and psychological causes rather than one single explanation.
What Are the Main Causes of Erectile Dysfunction?
The causes of ED can broadly be grouped as follows:
| Type of cause | Examples | How it may affect erections |
| Vascular and metabolic | High blood pressure, high cholesterol, cardiovascular disease, diabetes | May reduce or disrupt blood flow to the penis |
| Neurological | Nerve damage, multiple sclerosis, Parkinson’s disease, spinal injury | Can interfere with signals involved in erections |
| Psychological | Stress, anxiety, depression, performance anxiety | May disrupt arousal and the normal erectile response |
| Hormonal | Testosterone deficiency and other hormonal disorders | Can affect sexual desire and erectile function |
| Medication-related | Certain prescribed medicines | Sexual dysfunction can occur as a side effect |
| Surgery or trauma | Pelvic or prostate surgery and significant pelvic injuries | Can affect nerves or blood vessels involved in erections |
In practice, ED often involves more than one of these factors. Someone with diabetes, for example, may experience changes affecting both blood vessels and nerves. Repeated difficulties with erections can then create anxiety around sexual performance, adding another factor to the problem.
Physical Causes of Erectile Dysfunction
Reduced Blood Flow
Healthy circulation is important for achieving and maintaining an erection. Conditions affecting the blood vessels can reduce the amount of blood reaching the penis or make it more difficult to maintain an erection.
Possible contributors include:
- high blood pressure
- high cholesterol
- cardiovascular disease
- diabetes
- smoking-related vascular damage
Diabetes can be particularly relevant because it may affect both circulation and nerve function.
Persistent ED should therefore not automatically be viewed as an isolated sexual problem. Research has found an association between erectile dysfunction and cardiovascular events. A systematic review and meta-analysis of cardiovascular outcomes involving more than 150,000 participants found higher rates of several cardiovascular outcomes among men with ED. This is an association, however, and does not mean that ED itself directly causes cardiovascular disease.
Cardiovascular health may therefore form part of a broader clinical assessment when erection problems persist.
Current NICE cardiovascular risk guidance specifies QRISK3 when cardiovascular risk is being assessed in people with erectile dysfunction because this tool takes ED into account as a risk factor.
ED does not prove that cardiovascular disease is present, but persistent symptoms may prompt a clinician to consider cardiovascular risk as part of the wider assessment.
Nerve Problems
The nervous system carries signals between the brain and penis that are involved in developing and maintaining an erection. Damage or disruption to these pathways can therefore affect erectile function.
Neurological contributors can include:
- multiple sclerosis
- Parkinson’s disease
- spinal cord injury
- stroke
- nerve damage associated with diabetes
- nerve injury following pelvic surgery or trauma
Previous surgery can also be relevant. Operations involving areas such as the prostate, bladder or bowel can sometimes affect nerves involved in erectile function.
If erection difficulties developed following pelvic surgery or a significant injury, that history can provide useful information when the cause is being assessed.
Can Erectile Dysfunction Be Psychological?
Yes. Psychological factors can cause or contribute to erectile dysfunction, and they may also make an existing physical problem harder to manage.
Stress can interfere with sexual arousal. Anxiety may have a similar effect, particularly when the worry becomes focused on whether you will be able to get or maintain an erection.
A cycle can develop:
- You experience difficulty getting or keeping an erection.
- You worry that it will happen again.
- Increased anxiety makes natural arousal more difficult.
- Another episode reinforces the original concern.
Depression, relationship difficulties and wider emotional pressures can also affect sexual desire and erectile function.
Being able to achieve an erection at some times, such as on waking, but experiencing difficulty in particular sexual situations can provide useful information during an assessment. It does not establish the cause on its own.
Physical and psychological factors can also interact. A physical problem may contribute to the first episodes, while anxiety about sexual performance makes subsequent difficulties more persistent.
What Hormonal Problems Can Cause Erectile Dysfunction?
Hormones can influence sexual desire and erectile function.
Low Testosterone
Testosterone deficiency, or hypogonadism, can be associated with reduced sexual desire and erection difficulties in some men.
However, ED should not automatically be interpreted as evidence that your testosterone is low. Erectile dysfunction has many potential causes, and testosterone deficiency is diagnosed using the wider clinical picture rather than erectile symptoms alone.
Changes in libido or other symptoms may make a hormonal cause more relevant to investigate.
Other Hormonal Factors
Other endocrine conditions can also affect sexual function.
Where your symptoms or medical history suggest a possible hormonal cause, a GP or another appropriate clinician may recommend blood tests as part of the assessment.
Hormone treatment should follow an appropriate diagnosis rather than being based on erectile symptoms alone. If the underlying problem has another cause, hormone treatment may not address it.
Can Medicines Cause Erectile Dysfunction?
Some prescribed medicines can affect sexual function.
One example is antidepressant medication. The NHS lists reduced sex drive, difficulty reaching orgasm and difficulty getting or maintaining an erection among possible sexual side effects of antidepressants.
Other medicines may also affect erectile function, so it is worth mentioning all medication you take during an assessment.
If erection problems began after starting a medicine or changing the dose, speak to your GP or prescribing clinician.
Do not stop taking prescribed medication without medical advice. Your clinician can consider whether the medicine may be contributing and whether any change to your treatment is appropriate.
Can Lifestyle Factors Contribute to ED?
Temporary erection difficulties are common. Stress, tiredness and drinking too much alcohol can all affect sexual performance from time to time.
Longer-term lifestyle factors may also interact with physical causes of ED. Smoking can affect vascular health, while alcohol intake, physical inactivity and excess weight may form part of a wider cardiovascular and metabolic risk picture.
Factors that may be relevant during an assessment include:
- smoking
- alcohol intake
- physical activity
- body weight
- sleep
- cardiovascular health
- ongoing stress
None of these factors should be considered in isolation. Persistent erectile dysfunction should not simply be attributed to weight, fitness, alcohol or stress without considering other possible physical and psychological causes.
How Can You Find Out What Is Causing Your ED?
Trying to identify the cause yourself can be difficult because different conditions can produce similar symptoms.
An assessment may consider:
- when your symptoms started
- whether they happen consistently or only in certain situations
- whether you experience spontaneous or morning erections
- changes in sexual desire
- existing medical conditions
- cardiovascular risk factors
- current medicines
- smoking and alcohol consumption
- stress, anxiety and relationship factors
- previous pelvic surgery or injury
- symptoms that may suggest hormonal changes
A clinician may recommend blood tests or other investigations depending on your symptoms, medical history and initial assessment. Not everyone with ED will need the same tests.
Where pelvic-floor dysfunction, pelvic pain or related men’s health symptoms are present, our men’s health physiotherapy service provides specialist pelvic health assessment and treatment. Our assessment process can include taking a detailed medical history, physical examination and, where appropriate, assessment of pelvic-floor function.
ED tells us what is happening, but not necessarily why it is happening. Identifying the factors involved provides a better basis for deciding what type of care may be appropriate.
When Should You Get Help for Erectile Dysfunction?
An occasional problem getting or maintaining an erection is common and does not necessarily indicate an underlying medical condition.
Recurring or persistent difficulties are worth discussing with an appropriate healthcare professional, particularly if:
- ED is becoming more frequent or worsening
- there has been a noticeable change from your usual erectile function
- you also have reduced sexual desire
- symptoms appeared following pelvic surgery or injury
- you have diabetes or cardiovascular risk factors
- you think medication may be contributing
- the problem is causing significant anxiety or affecting your relationship
Seeking an assessment is not simply about finding a way to achieve an erection. It can also help establish whether physical, psychological, medication-related or other factors may be contributing to the problem.
Treatment Should Be Based on the Cause
There is no single treatment that is appropriate for every case of erectile dysfunction.
Someone whose ED has a vascular component may require a different approach from someone whose symptoms are associated with medication, nerve damage, hormonal changes or psychological factors.
Depending on the cause and individual circumstances, management may involve addressing an underlying health condition, reviewing medicines with the prescribing clinician, psychological support or addressing relevant lifestyle factors.
Where assessment identifies pelvic-floor dysfunction or related pelvic symptoms, physiotherapy may form part of the wider management plan.
As part of our men’s health services at Core Body Clinic, we also offer clinician-led shockwave therapy for erectile dysfunction. Whether this treatment is appropriate depends on your symptoms, medical history and clinical assessment. We do not assume it is suitable for every person with ED or every underlying cause.
If erection difficulties are recurring and you would like to understand whether this option could be relevant to your circumstances, find out about our shockwave therapy for erectile dysfunction and how to discuss your symptoms with our team.
The priority is working out which factors may be contributing to your symptoms. Once the likely causes are clearer, you and the appropriate healthcare professional can discuss which management options are relevant to your individual situation.