Erectile Dsyfunction

Written by Dr Laura Wiemer,
Urologist and Medical Director at Kranus Health

What is erectile dysfunction (ED)?

Erectile dysfunction, or ED for short, is the consistent or recurrent absence of an erection of the penis during sexual arousal and/or the absence of an erection of the penis sufficient for sexual intercourse. According to the medical definition, erection problems are classed as erectile dysfunction only when symptoms last at least 6 months and prevent satisfactory sexual intercourse in more than 70% of cases.

There are different levels of severity in erectile dysfunction that range from mild to complete erectile dysfunction. How severe your problems are is determined by a simple questionnaire. The score is used, among other things, as a comparative value to measure the improvement in your erection after having completed successful treatment. This value is called the IIEF score.

How does erectile dysfunction manifest itself?

Some men have erection problems only in situations of sexual intercourse with a partner, others can not obtain a spontaneous erection in the morning. Some men will obtain an erection, but struggle to maintain it long enough. In other words, erectile dysfunction is a multifaceted condition. The diversity in erection problems is best explained with the equally diverse underlying root causes of erectile dysfunction.

How many men are affected by erectile dysfunction?

In Germany alone, probably 6-8 million men are affected by erectile dysfunction (1). However, the actual number remains uncertain as erection problems are widely considered a taboo topic and men have difficulties talking about them. In consequence only slightly more than half of the affected men consult a health care professional (2). What we do know for sure: The frequency (prevalence) of men suffering from erectile dysfunction increases with age. Nearly one in two men over the age of 50 is affected (3), nonetheless as many as 8% of 20-29 year old men (2) are also dealing with erection problems.

Why do erection problems occur?

During sexual stimulation the brain sends signals to the penis through the spinal cord and nerves. This causes arteries to dilate and blood to flow into the penis. The increased pressure makes the penis hard. Blood outflow is simultaneously slowed down by compressing the veins in the penis. As long as the inflow of blood is greater than the outflow, the erection is maintained. Every part of this system, that is, thoughts, nerves and blood vessels, must play its part to enable a healthy lasting erection. There are different reasons why the system can be disturbed and erection problems occur. Often it is not one reason alone that leads to erectile dysfunction but a combination of different causes.

Possible causes of erectile dysfunction are (4) :

  1. psychological causes, such as stress, insecurity and fear of failure
  2. Arterial or venous problems that cause blood flow to and from the penis to malfunction
  3. hormonal disorders, such as the lack of testosterone
  4. anatomical reasons that may be induced by a pre-existing condition
  5. side effects that can result from taking drugs and other substances
  6. nerve damage caused by surgery, accidents or other conditions

What is the difference between erectile dysfunction, impotence and sterility?

Impotence is a vaguely defined generic term that also includes the inability to reproduce (sterility). This is why strictly speaking impotence should not be used as a synonym for erectile dysfunction.

Are erectile dysfunctions dangerous?

Having erection problems is not dangerous in itself. However, they can be an early warning signal indicating future heart attacks or strokes. There is a saying that the penis is the antenna of the heart. It refers to the fact that arteriosclerosis, i.e. calcification or blocking of the vessels, manifests much earlier in the small blood vessels of the penis than in the larger coronary vessels of the heart (5). To counteract arteriosclerosis specialists advise regular physical activity and a healthy lifestyle including a healthy diet.

How can urologists help?

If you are dealing with erectile dysfunction an urologist is who you should be consulting - not only from a medical point of view. Urologists are familiar with the condition and treat patients with erectile dysfunction on a regular basis. They are medical experts and offer a safe space to address an issue that is still considered a taboo in other contexts. Your urologist will also advise whether it is necessary to perform further diagnosis, such as taking a blood sample or doing an ultrasound, or whether other medical conditions need to be further considered.

Additionally, your urologist can now prescribe the first digital therapie to treat not only the symptoms but also the root causes of erectile dysfunction, the Kranus Edera app. Together with the patient an urologist will also decide whether further or supplementary treatment is indicated, e.g. supplementary oral medication with PDE5 inhibitors.

What are the treatment options for erectile dysfunction?

Treating the root causes of erectile dysfunction is the most important therapy option. Studies show good efficacy of physical activity and pelvic floor training (6,7). Changing some of your lifestyle choices and habits is also an essential component of the therapy. Psychological issues have also been seen to play a major role in erection problems (8,9). This is why psychotherapy and/or sex therapy can be a helpful treatment option. Designated therapie for couples may also be a good solution.

Oral medication with PDE5 inhibitors can support a holistic therapy approach addressing the root causes of erectile dysfunction. The most famous drugs for erection problems are phosphodiesterase-5 inhibitors (PDE-5 inhibitors). They are commonly better known as the little "blue pill". Other patients achieve positive results using a penis ring or a vacuum pump. Another treatment option is to inject a drug into the penis or into the urethra (canal that carries off urin). If none of these has a sufficiently positive effect, there are further physical treatment options, such as shock wave therapy or - usually chosen as the last option - the installation of a penile prosthesis.

What are PDE-5 inhibitors, commonly also referred to as little “blue pills?

Phosphodiesterase-5 inhibitors (PDE-5 inhibitors) are the drugs most commonly used to treat erectile dysfunction. Depending on the brand the drugs contain the following active ingredients: sildenafil, tadalafil, vardenafil, avanafil. They all work by inhibiting the enzyme phosphodiesterase-5 which results in increased blood flow to the penis. Depending on the active ingredient used there will be differences regarding the amount of time the drug takes to kick-in, the duration of drug action and regarding side effects of which some can be rather unpleasant (10).

In 60-80% of patients there is an improvement in erection as a result of taking these drugs (12). Unfortunately, there is no lasting effect and only 16% of patients take the tablets as a long-term solution (2). PDE-5 inhibitors are available on prescription only as they can cause health risks combined with other drugs and/or specific health conditions. Health insurances do not cover the costs for PDE5-inhibitors. The use of PDE-5 inhibitors in addition to a therapy addressing the root causes of erectile dysfunction can be beneficial.

How can the digital therapeutic Kranus Edera help with erection problems?

The CE-certified digital health app Kranus Edera closes a gap in our healthcare system: men affected by erectile dysfunction finally have the means to address not only the symptoms, but also the root causes of their erection problems with a holistic approach which will improve their quality of life and erectile function sustainably.
Kranus Edera is 100% based on science and puts the national and EAU healthcare guidelines into place that suggest treating the underlying causes of erectile dysfunction and inducing positive lifestyle changes.

The success of treating erectile dysfunction with the Kranus Edera app is based on a multimodal therapy approach including digital coaching, a pelvic floor trainer, cardiovascular training, physiotherapy exercises, mental and sex therapy exercises as well as background knowledge for patient education.

What is the IIEF score?

The International Index of Erectile Function (IIEF) is an internationally validated questionnaire used to assess the severity of erectile dysfunction and to evaluate the success of therapy. Originally, the questionnaire consists of 15 questions. The IIEF-5 questionnaire is limited to those questions directly related to erection problems.

Based on the result of the questionnaire, the patient is placed into one of the following categories. The final score is obtained by adding up the individual question scores:

22-25 points no erectile dysfunction
17-21 points mild erectile dysfunction
12-16 points mild to moderate erectile dysfunction
8-11 points moderate to severe erectile dysfunction
below 8 points severe erectile dysfunction (11)

Further information

The medical guidelines on erectile dysfunction are aimed at medical professionals but can be accessed online by anyone interested:

Kranus Health
Laura Wiemer, MD, is urologist and part of the experienced medical team at Kranus Health. Get to know us here.


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  2. Rosen, R. C., et al. (2004). "The multinational Men's Attitudes to Life Events and Sexuality (MALES) study: I. Prevalence of erectile dysfunction and related health concerns in the general population." Curr Med Res Opin 20(5): 607-617.
  3. Feldman, H. A., et al. (1994). " Impotence and its medical and psychosocial correlates: results of the Massachusetts Male Aging Study." J Urol 151(1): 54-61.
  4. EAU Guidelines. Edn. presented at the EAU Annual Congress Amsterdam 2020. ISBN 978-94-92671-07-3.
  5. Baumhakel, M. and M. Bohm (2007). "Erectile dysfunction correlates with left ventricular function and precedes cardiovascular events in cardiovascular high-risk patients." Int J Clin Pract 61(3): 361-366.
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  8. Bossio, J. A., et al. (2018). "Mindfulness-Based Group Therapy for Men With Situational Erectile Dysfunction: A Mixed-Methods Feasibility Analysis and Pilot Study." J Sex Med 15(10): 1478-1490.
  9. Sommers, F. G. (2013). "Mindfulness in love and love making: a way of life." Sexual and Relationship Therapy 28(1-2): 84-91.
  10. Kedia, G. T., et al. (2020). "The Use of Vasoactive Drugs in the Treatment of Male Erectile Dysfunction: Current Concepts." J Clin Med 9(9).
  11. Rhoden, E. L., et al. (2002). "The use of the simplified International Index of Erectile Function (IIEF-5) as a diagnostic tool to study the prevalence of erectile dysfunction." Int J Impot Res 14(4): 245-250.
  12. Kalsi, J.S.; Kell, P.D. Update on the OralTreatments for Male Erectile Dysfunction. Eur. Acad. Dermatol.Venereol. 2004, 18, 267–274.