Erectile Dysfunction Causes

There are various causes of ED - it can be physical (a ‘hardware’ problem) or psychological (mental health effects - ‘the software’)

For an individual to have a healthy and sustainable erection, three aspects of the body’s process should be working well. The blood flow (BF), nerve supply, and the balance of sex hormones. Problems and/or disruptions in any of these processes can lead to ED. The following conditions give further details to the causes of ED.

Physical causes

Medical conditions

Health conditions such as peripheral artery disease, atherosclerosis, diabetes, hypertension, obesity, etc, can cause reduced blood flow to the penis due to artery narrowing. Furthermore, injury to the spinal cord or radiation therapy can disrupt or harm nerves present in the penis. 

Nerve damaging pelvic injury 

Hormonal disruption

- Increased or decreased testosterone production 
- Increased prolactin production 
- Increased steroid usage causes testosterone suppression 
- Increased or decreased thyroid hormone production 
- Increased growth hormone production
- Penis abnormalities
- Phimosis/Paraphimosis
- Peyronie’s disease

Men with low sexual desire such as in Hypoactive Sexual Desire Disorder (HSDD) can also present with arousal concerns such as ED.

Psychological causes

The smooth working of physical hardware or genitalia isn’t the only thing needed for sex to be satisfying and comfortable. The mind and body, together, affect the sexual arousal phases. Some mental health concerns that can lead to ED include

- Anxiety and/or anxiety disorders such as OCD
- Depression 
- Chronic stress: Stress hormones cortisol and adrenaline cause sex hormone suppression
- Performance Anxiety 
- Interpersonal concerns among couples
- Abuse


There are a variety of medication classes that can result in ED as a negative side effect. These classes of medications treat the following conditions:

- Hypertension drugs: some of these can negatively affect penis blood flow 
- Cholesterol drugs (specifically some of the Statins): can lower testosterone levels
- Psychiatric drugs: some medications in some people can disrupt brain chemical signaling which affects sexual function 
- Chemotherapy: can cause nervous system damage
- Cardiovascular drugs: can cause low testosterone production in some patients 
- Pain killers: Opioids can reduce testosterone levels in some patients 


Recreational drug usage can affect an individual’s ability to get and sustain an erection especially when people abuse them or are addicted to them in the following mechanisms 

- Alcohol: causes dehydration (reduces sensation in genitals), lowers testosterone (lowers sexual desire) levels and is a depressant (suppresses blood circulation and nerve sensitivity).
Nicotine: Disrupts blood circulation and negative effects on the arousal phase of the sexual response cycle.
Cannabis: Can prevent smooth muscle relaxation needed for penis blood flow and erection.
Cocaine: Post effects of the drug can cause delayed ejaculation, can lower sperm count, and can cause ED.
- Porn addiction can also be a cause of ED due to the stimuli desensitisation