Erectile dysfunction: causes and treatment

Which triggers erectile dysfunction can have, which therapies help

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Erectile dysfunction - briefly explained

  • Erectile dysfunction (ED) means that more than two-thirds of the attempts a man cannot get or maintain an erection sufficient for sexual intercourse. The penis does not become hard enough or sags prematurely.
  • The erectile dysfunction lasts for at least six months. So if it "doesn't work" every now and then, it is not immediately a disorder that requires treatment.
  • Erectile dysfunction often has physical causes, such as circulatory disorders. A testosterone deficiency can also be a trigger. Purely psychological triggers occur mainly in younger men.
  • The therapy is often carried out with drugs, so-called phosphodiesterase-5 inhibitors (PDE-5 inhibitors). But there are other treatment options.

Erectile dysfunction is colloquially called erectile dysfunction, erectile dysfunction, erectile dysfunction or impotence. That is actually imprecise. Because these terms sometimes describe other disorders or summarize several disorders that do not necessarily belong together - on the one hand erectile dysfunction such as erectile dysfunction or premature ejaculation, on the other hand infertility, i.e. the inability to father children.

How common is erectile dysfunction?

Erectile dysfunction becomes more common with age. Erectile dysfunction affects almost every tenth man among 40 to 49 year olds, and every third man among 60 to 69 year olds. This was shown by a study by the University of Cologne in 2000. Many other studies in numerous countries came to comparable results. Experts suspect that there is a large number of unreported cases. So the actual numbers could be higher.

Especially in men over 50 years of age, erectile dysfunction can be the first warning sign of vascular disease (arteriosclerosis) - and thus a possible harbinger of heart attack or stroke. Early therapy can prevent dire consequences. For this reason alone, it is advisable to have any potency problems clarified by a doctor.

Causes: how does erectile dysfunction occur?

Physical and psychological triggers can mix in erectile dysfunction. If men suffer from physical potency problems, this can easily lead to additional psychological problems.

Purely psychological causes are mainly found in younger men. In addition to conflicts in the partnership, stress, problems or anxiety disorders, depression is very often associated with erectile dysfunction.

In men aged 50 and over, it is primarily physical causes that trigger erectile dysfunction.

Circulatory disorders

Most often, the penile blood flow is disturbed and / or the penile muscles themselves, which are very similar to the vascular wall muscles, become ill. Either too little blood arrives in the penis because the arteries supplying it are "calcified" (arteriosclerosis). Or the blood drains too quickly through the veins. Or both. In any case, the amount of blood in the erectile tissue of the penis is no longer sufficient for a satisfactory erection.

Various diseases that promote circulatory disorders also increase the risk of erectile dysfunction:

  • Diabetes mellitus
  • high blood pressure
  • Lipid metabolism disorders

Lifestyle also has a decisive influence: Smoking, obesity, lack of exercise and a one-sided and unhealthy diet clog the blood vessels and increase the likelihood of potency problems.

Testosterone deficiency

A sufficiently high level of the male sex hormone testosterone is an important prerequisite for a satisfactory erection. With age, the testosterone level in the blood of men usually falls. A testosterone deficiency (hypogonadism) does not have to, but can lead to erection problems. Therefore, low testosterone levels should be considered as a possible cause (see Therapy section).

Drug side effect

Drugs can cause erectile dysfunction as a side effect, including beta blockers for high blood pressure, dehydrating drugs, lipid-lowering drugs or drugs for depression. If there is a corresponding note in the package insert and there is a suspicion that the drug could trigger erectile dysfunction, patients should consult their doctor. Another preparation may be prescribed. Caution: Do not discontinue or change medication on your own!

Other causes

In order for an erection to occur, not only the blood flow to the penis has to be right. All the nerve tracts involved - from the penis to the spinal cord to the brain - must also be intact.

Herniated discs, injuries, radiation or operations in the pelvic area or on the spinal cord can result in erectile dysfunction. Likewise, diseases that can cause damage to peripheral nerves (a neuropathy) - such as diabetes mellitus (diabetes) or chronic alcohol abuse.

Other possible causes of erectile dysfunction are diseases that affect the central nervous system: for example multiple sclerosis, Parkinson's disease, Alzheimer's dementia or a stroke.

Obstructive sleep apnea can also be linked to erectile dysfunction. Serious illnesses - such as cancer, severe kidney or liver problems - can always affect potency.

Erectile dysfunction: symptoms

In erectile dysfunction, the man cannot get or keep an erection sufficient for sexual intercourse. The penis does not get hard enough and / or recreate quickly. The problems drag on for at least six months and occur in more than two-thirds of the cases.

Signs suggestive of physical causes:

  • erectile dysfunction develops gradually
  • it occurs both in intercourse with the partner and in masturbation
  • normal erections during sleep, which occur in any healthy man, fail to occur

Signs that suggest psychological causes:

  • erectile dysfunction occurs suddenly, possibly after stressful life events
  • Erectile dysfunction mostly only occurs in certain situations
  • the man is younger than 50 years

Diagnosis: how do you determine erectile dysfunction?

The first point of contact is usually the general practitioner’s practice. If necessary, she can refer you to the appropriate specialist practice - usually a urology practice. Depending on the cause, specialists from other disciplines are required, for example from neurology, psychotherapy, psychology, andrology (men’s medicine) or sex therapy.

Conversation: At the beginning, the doctor will get a precise picture of the disorder by asking specific questions. Standard questionnaires help to record symptoms precisely. It is also of interest whether operations have taken place or whether there are diseases that could possibly trigger erectile dysfunction, such as diabetes mellitus (diabetes), high blood pressure, intervertebral disc problems. Sometimes the potency problems are also a side effect of a drug. That is why it is recorded which medication the patient is taking. The doctor also asks whether spontaneous erections are noticed at night or in the morning. In every healthy man, erections occur during certain phases of sleep. If they fail, that makes an organic cause more likely. It can be helpful if the partner is included in the medical discussion.

Physical examination: This is followed by a physical examination focusing on the genital organs and prostate. Since many erectile problems can be traced back to circulatory disorders, the vascular pulses in the arms and legs as well as the blood pressure are also checked.

Blood test: A blood test provides information on possible risk factors such as high blood sugar or unfavorable blood lipid values. It can also be used to determine whether there is a deficiency in the male sex hormone testosterone. To determine in which range the testosterone level is moving, a blood test in the morning hours is suitable, because the hormone concentration fluctuates over the course of the day. The highest values ​​can be expected in the morning.

Further investigations

Only in very few cases does the doctor need further examinations: The blood flow in the vessels of the penis can be checked with a special ultrasound examination (Doppler sonography). For this purpose, a drug that triggers an erection may be injected into the penis (cavernous body injection test). Whether and how well an erection is achieved in this test provides additional information.

If arterial disorders are found, it is advisable to also examine the heart. Erectile dysfunction can be an early sign of arteriosclerosis and thus a (still asymptomatic) coronary artery disease.

Nerve examinations will show whether nerve disorders may be the cause of the problems. To do this, the doctor uses weak electrical impulses, for example, and checks whether these signals are being passed on by the nerves as expected.

A measuring device can be used to register spontaneous erections during sleep, for example in a sleep laboratory (nocturnal penile tumescence measurement).If the values ​​are normal, this is an indication that an erection is possible without any problems. Psychological causes are then more likely, physical ones less likely, but not excluded.

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Therapy: what helps with erectile dysfunction?

If feasible, the doctor will fix the specific cause of the erectile dysfunction - for example, prescribe a different medication if the erectile dysfunction is caused by a medication side effect. (Caution: never discontinue or change medication on your own!)

Most of the time, only erectile dysfunction symptoms can be treated. There are several options here. What helps best in individual cases is an individual decision, which should be made after detailed medical advice on possible side effects and risks.

Compensate for lack of testosterone

With increasing age, the testosterone level in the blood drops somewhat in almost all men. This is nothing unusual and also no reason for therapy. However, if a man suffers from erectile dysfunction, a testosterone deficiency (hypogonadism) could play a decisive role. In this case, your doctor will advise you to compensate for the hormone deficiency. This may already improve the potency problems. Drugs against erectile dysfunction (PDE-5 inhibitors, see below) often work better or for the first time together with hormone therapy.

Some men with erectile dysfunction even benefit from testosterone administration, even though their blood values ​​are actually in a nearly normal range. When the hormone administration makes sense, it is best to decide individually in a medical consultation. The testosterone is applied to the skin in the form of a gel or injected into the muscle at longer intervals.

At first, research seemed to suggest that testosterone therapy could potentially increase the risk of prostate cancer or a heart attack. More recent studies have shown, however, that a medically indicated and monitored testosterone replacement therapy neither increases the risk of prostate cancer nor promotes a heart attack. Those affected should nevertheless obtain detailed information about the possible advantages and disadvantages of the treatment in a medical consultation.

Medication: Phosphodiesterase-5 inhibitors (PDE-5 inhibitors)

In Germany, various phosphodiesterase-5 inhibitors (PDE-5 inhibitors) are approved for the treatment of erectile dysfunction. The first was Sildenafil, which was launched in 1998. It was followed by Tadalafil, Vardenafil and Avanafil. All require a prescription. Effect and side effects are roughly comparable. The tablets help around 70 to 80 percent of those affected and differ mainly in dosage and duration of action. Sildenafil, vardenafil and avanafil work after about 15 to 60 minutes (the onset of action can be delayed with sildenafil and vardenafil after high-fat meals). Their effect lasts for around four (to twelve) hours. Tadalafil works for around 24 to 36 hours after around 30 minutes. This medication can also be prescribed as a long-term medication with one tablet per day.

Background: How do phosphodiesterase 5 inhibitors work?

As the name suggests, the drugs inhibit phosphodiesterase-5 (PDE-5), which is an endogenous enzyme. This enzyme normally breaks down a certain messenger substance that is produced more intensely during sexual arousal and increases the blood flow in the penis. If the enzyme phosphodiesterase-5 is now hindered in its work by the drugs, more messenger substance remains. As a result, blood flow to the penis increases, an erection occurs or lasts longer. A second effect is that the blood pressure in the pulmonary circulation drops. Phosphodiesterase 5 inhibitors are therefore also used to treat pulmonary hypertension.

PDE-5 inhibitors only work when the man is sexually aroused. So they do not increase the desire. The erection ends - as without medication - with orgasm or ejaculation. However, further erections are possible within the duration of the effect.

Possible side effects include headache, facial flushing, heartburn, nasal congestion, temporary changes in color vision with sildenafil and vardenafil, and muscle and back pain with tadalafil. Detailed information can be found in the instruction leaflet.

PDE-5 inhibitors are not suitable for patients for whom the doctor has prescribed nitrates or molsidomine, because they can lead to a dangerous drop in blood pressure. Nitrates or molsidomine are used, for example, in the treatment of angina pectoris in coronary artery disease. Caution is also advisable when combined with α1-receptor blockers, which are often prescribed for benign prostate enlargement. Some illnesses (such as severe liver disease, heart disease or a history of stroke) can also speak against taking PDE-5 inhibitors.

PDE-5 inhibitors require a prescription for a good reason. Before using it for the first time, patients should consult a doctor for detailed information on side effects and possible individual risks. Statutory health insurance providers usually do not pay for the medication.

Doctors expressly warn against purchasing products yourself from dubious (Internet) providers. Samples have repeatedly shown that many drugs are counterfeited internationally, that they may contain ingredients other than those described, or that the dose information is incorrect. If you get involved, you risk your health, in the worst case even your life.


Another active ingredient for the therapy of erectile dysfunction is yohimbine, which works in the brain and is mainly used in the case of mentally caused erectile dysfunction.

SKAT = cavernous body autoinjection therapy

If PDE-5 inhibitors cannot be taken or do not work, for example because of nerve damage, erectile tissue autoinjection therapy (SKAT for short) is an option.

The man injects a drug into the erectile tissue of the penis with a very thin needle. The medicine causes more blood to flow into the penis. An erection occurs after about 10 to 15 minutes and lasts for about an hour. For most users, the injection is unproblematic and not painful.

Correct dosage is important. An overdose can result in an erection that lasts for hours and requires medical attention, otherwise it will damage the penis. Various diseases (including leukemia or sickle cell anemia) can speak against the use.

Whether the method is suitable in each individual case and how it works in detail should be discussed with the doctor on an individual basis. The statutory health insurance usually pays for this therapy when it is prescribed.

MUSE = Medicinal urethral system for erection

Active ingredients can also be administered via the urethra in the form of a "mini suppository". This principle is called MUSE (Medicinal Urethral System for Erection).

The man brings a certain prostaglandin into the urethra with the help of an applicator. The active ingredient reaches the erectile tissue of the penis through the urethral wall. The blood flow increases. An erection occurs after about 10 to 15 minutes and lasts for 30 to 60 minutes.

Possible side effects are pain in the penis, burning sensation in the urethra, headache, dizziness. Various diseases (including leukemia or sickle cell anemia) can speak against the use. If the partner is pregnant, a condom should be used as a precaution to reduce the risk of premature labor.

Whether MUSE is suitable in individual cases and what needs to be considered should be discussed individually with the doctor or read in the package insert.

Principle of vacuum therapy

© W & B / Jörg Neisel / Szczesny

Vacuum therapy

In this method, a transparent plastic cylinder with a suction pump is placed on the penis and negative pressure is created. Increased blood flows into the erectile tissue, creating an erection. A rubber ring at the base of the penis prevents the blood from flowing back. It has to be removed after 30 minutes to avoid circulatory problems and damage to the penis. If the vacuum pump is prescribed by a doctor, the statutory health insurance usually pays.

Refillable erectile tissue implant

© W & B / Jörg Neisel / Szczesny


In some cases only implants made of silicone, which are inserted into the erectile tissue during surgery (erectile tissue implants), help. This intervention is irreversible and should therefore be carefully considered and planned. There are different variants: The most commonly used implants are refillable. A reservoir containing saline solution is implanted in the lower abdomen. Doctors insert a small pump into the scrotum. At the "push of a button" the man can fill the implant so that a kind of erection is created. Other implants are always stiff but flexible.

Counseling or psychotherapy

In most cases, the physical and emotional causes of erectile dysfunction cannot be separated in detail. Talking to a sex therapist - ideally together with your partner - can help with mentally caused erectile dysfunction. But men with organic potency problems often benefit from it too.


The European Association of Urology (EAU) names extracorporeal shock wave therapy (ESWT) as a further treatment option for erectile dysfunction. However, there are only a few studies on this. The benefit has not yet been proven and is highly questionable.

Can erectile dysfunction be prevented?

A healthy lifestyle lowers the risk of circulatory disorders and thus also of erectile dysfunction. Those who adjust their lifestyle can also have a positive effect on an existing erectile dysfunction. In detail this means:

  • do not smoke
  • eat a balanced diet
  • drink little alcohol
  • move a lot
  • Lose excess weight
  • Regularly check blood pressure, blood sugar, blood lipids and treat disorders

Professor Dr. Christian step

© W & B / private

Consulting expert

Professor Dr. Christian Stief is a specialist in urology. He completed his habilitation in 1991 at the Hannover Medical School. Since 2004 he has been Director of the Urological Clinic at the University of Munich Clinic. He is the editor of several German and English-language scientific books and was co-editor of the journal European Urology from 2006 to 2012. Since 2018 he has been a member of the medical committee of the Science Council of the federal government and the federal states.


Haensch C.-A. et al., Diagnosis and Therapy of Erectile Dysfunction, S1 Guideline, 2018; in: German Society for Neurology (ed.), guidelines for diagnostics and therapy in neurology. Online: (accessed November 2019)

Urologist portal: erectile dysfunction. Online: (accessed November 2019)

Urologist portal: Scientific statement of the DGA e.V., DGU e.V and the BvDU e.V. on patient information "Testosterone in older men: Menopause in men - does it exist?" in the KBV circular. Online: in-older-men-menopause-men-is-there-in-kbv-Rundbrief.html (accessed November 2019)

EAU guidelines. Edn. presented at the EAU Annual Congress Barcelona 2019. ISBN 978-94-92671-04-2. Online: (accessed November 2019)

Braun, M. et al: Epidemiology of erectile dysfunction: results of the Cologne Male Survey, In: Int J Impot Res 12, 305-311

Glenn R Cunningham, MD, Raymond C Rosen, PhD, Overview of male sexual dysfunction, d. UpToDate. Waltham, MA: UpToDate Inc. (Retrieved November 2019)

Mohit Khera, MD, MBA, MPH, Glenn R Cunningham, MD, Treatment of male sexual dysfunction, ed. UpToDate. Waltham, MA: UpToDate Inc. (Retrieved November 2019)

Important NOTE:

This article is for general guidance only and is not intended to be used for self-diagnosis or self-treatment. It cannot replace medical advice. Please understand that we do not answer individual questions.

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