Erectile dysfunction: causes, assessment and treatments

What it is and why it happens

Erectile dysfunction is the persistent difficulty in getting or keeping an erection firm enough for satisfying sex. It is a common reason for seeing a doctor: in a study of almost 2,500 Spanish men aged 25 to 70, between 1 in 8 and 1 in 5 had it, depending on how it was measured, and it became more common with age.

An erection depends on good blood flow to the penis, on the nerves, on hormones and on the mind. That is why the causes vary, and several are often combined:

• Blood vessels. Smoking, high blood pressure, high cholesterol, excess weight and lack of exercise damage the arteries, including those of the penis.
• Diabetes. It affects both blood vessels and nerves.
• Hormones. Low testosterone, which often comes with lower sex drive and tiredness, and some thyroid problems.
• Medicines and drugs. Some blood pressure treatments, antidepressants, hormone treatments for prostate cancer, excess alcohol and other drugs.
• Psychological causes. Stress, anxiety, depression or relationship problems. They often add to a physical cause.
• Pelvic surgery or radiotherapy. For example, treatment for prostate cancer.

A warning sign for the heart

Erectile dysfunction shares risk factors with heart and artery disease, and it can be one of its first signs. In an analysis of 12 studies with more than 36,000 men, those with erectile dysfunction had almost 50% higher risk of cardiovascular disease.

That is why it deserves a check-up, even if you feel well: blood pressure, blood sugar and cholesterol. Looking after these factors helps your heart and, often, your erections too.

How it is assessed

1. The conversation. What your erections are like with a partner and in the morning, how long the problem has lasted, your sex drive, ejaculation, your medical conditions, your medication and your habits. If you wish, your partner can come with you.
2. A questionnaire. The IIEF-5 has five questions and helps to measure how severe the problem is and, later, how well treatment is working. You can look at it before your appointment using the link to the IIEF-5 questionnaire in the tools section. It gives guidance, but does not explain the cause.
3. The examination. The genitals are examined and your blood pressure is taken.
4. A blood test. Glucose, cholesterol and testosterone, the latter in the morning and fasting. It helps to uncover problems that can be treated, such as undiagnosed diabetes or low testosterone.
5. Penile Doppler ultrasound, only in some cases. It measures blood flow in the penis during an erection triggered with a medicine. It is used when a blood vessel cause is suspected, when tablets do not work, to assess suitability for shockwave therapy or if the penis is curved.

Treatments, step by step

The European Association of Urology (EAU) 2026 guidelines do not set out rigid steps: treatment is chosen with you according to your health, your preferences, how effective it is and how invasive it is. This is the usual order:

Lifestyle and risk factors

This comes first, before or alongside other treatments: stopping smoking, exercising (especially aerobic exercise), losing weight and controlling blood pressure, blood sugar and cholesterol. Your medication is also reviewed, but do not stop any of it on your own. If testosterone is low, treating it may help. If there is a psychological component, sex therapy or cognitive behavioural therapy, ideally with your partner, improves results.

Tablets

Phosphodiesterase type 5 (PDE5) inhibitors are the first-line medicine. Four are approved in Europe, with similar effectiveness; they differ mainly in how long their effect lasts. They do not cause an erection on their own: sexual stimulation is needed. The most common side effects, such as headache, facial flushing, indigestion or a blocked nose, are usually mild. Only take them on prescription.

Local treatments

Alprostadil is a medicine applied to the penis itself. It can be used as a cream, applied to the opening at the tip of the penis, or as a small pellet inserted into the urethra; this is less invasive, but also less effective. It can also be injected into the penis (intracavernous injections): you learn how to do it at the clinic and it produces an erection in more than 7 in 10 men, although many stop using it over time. It can cause pain and, sometimes, an erection that lasts too long.

Low-intensity shockwave therapy

A treatment without medicines or surgery for some cases with a blood vessel cause. I explain it below.

Vacuum device

A cylinder placed over the penis draws blood in by creating a vacuum; a ring at the base keeps the erection. It involves no medicines. The ring should not be left on for more than 30 minutes, and it is not suitable if you take anticoagulants or have a bleeding disorder.

Penile implant

A permanent solution when other treatments do not work or are not suitable, or if you prefer it. I explain it below.

Focused low-intensity shockwave therapy

This is a treatment with focused low-intensity shockwaves: a device concentrates the waves on the penis to improve its blood flow. It is done in several short sessions at the clinic, with no anaesthetic or sedation and no hospital stay. You may feel a slight tickling, and you can go about your normal activities the same day.

It is intended for erectile dysfunction with a blood vessel cause, including in men for whom tablets work poorly. It is not suitable when the cause is hormonal, neurological or purely psychological. If you take tablets (PDE5 inhibitors), you can keep taking them until the effect appears.

The 2026 European guidelines state, as a weak recommendation (the expected benefit is more limited or less certain), that it can be offered, alone or together with tablets:

• In mild erectile dysfunction with a blood vessel cause.
• As an alternative, if you do not want to or cannot take tablets.
• If you have a blood vessel cause and tablets work poorly for you.

It is worth knowing what to expect. According to the guidelines, the improvement is mild to moderate, and between 4 and 8 in 10 men find it satisfactory. Some men notice a change from the first few weeks, although the improvement is usually assessed 1 to 3 months after the sessions end. The effect is not permanent: it can last for months and tends to wear off over time, and the treatment can be repeated. Results depend on the type of device and the protocol: one trial with radial waves found no difference compared with a sham treatment.

Penile implant

It is an operation in which cylinders are placed inside the penis. It may be an option if other treatments do not work or are not suitable for you, or if you prefer a permanent solution. There are two types:

• Inflatable. The cylinders are filled with fluid using a small pump placed inside the scrotum; three-piece devices also have a small reservoir in the lower abdomen. It sits entirely inside the body and the erection is closer to a natural one.
• Semi-rigid. The penis stays firm and is moved by hand into the position you want. It is simpler to fit and to use, but harder to conceal.

Satisfaction is high: in a review of 83 studies with more than 12,000 men, about 8 in 10 were satisfied with their implant.

Its two main risks are:

• Infection. In a first implant, with current prevention measures, it occurs in about 2 or 3 in 100 men, and in fewer with coated implants. It is more common in men with diabetes. If the implant becomes infected, it usually has to be removed.
• Mechanical failure. Over time, the implant can break down and need replacing. In an analysis of more than 20,000 men with an inflatable implant, about 87 in 100 were still working without needing replacement or removal at 5 years, and about 77 in 100 at 10 years.

It is a permanent decision: if the implant ever had to be removed, the other treatments usually no longer work. That is why it is decided calmly and with full information.

Who treats them

Dr. Mario Domínguez Esteban is a urologist and Head of the Uro-Oncology Section at Marqués de Valdecilla University Hospital. In the private sector he sees patients at Urología Mínimamente Invasiva (UMI), in Santander (healthcare registration no. 06/2016/02769, medical consultation, urology). There he assesses erectile dysfunction and treats it with tablets, local treatments and focused low-intensity shockwave therapy, using the clinic's own equipment.

Warning signs

• Seek urgent medical attention if you have an erection lasting more than 4 hours (priapism), or if you have chest pain, shortness of breath or severe dizziness during or after sex.
• Book a priority appointment with your doctor if your erectile dysfunction is new and you have cardiovascular risk factors (smoking, high blood pressure, diabetes, high cholesterol or excess weight), if you also notice lower sex drive or marked tiredness, if it started when you began a new medicine (do not stop it on your own) or if a curve or a lump appears in your penis.

Never combine erection tablets (PDE5 inhibitors) with nitrates, such as glyceryl trinitrate (nitroglycerin) for angina in tablet, patch or spray form, or with “poppers”: the combination can lower your blood pressure dangerously. Always tell your doctor about all the medication you take.

There is more detail in the warning signs.

Frequently asked questions