Brief Answer:
Both psychological and physical factors may be responsible.

Detailed Answer:
Hi
Thanks for posting your query on HCM.
I appreciate your concern for your husband.
The most common Psychological factors:
Poor communication with partner, alcoholism, anxiety depression, fatigue and smoking and drug abuse.

The most common Physical factors:
Diabetes, Hypertension, Prostate cancer, Spinal cord injury, Neurological diseases, heart disease Peyronie's disease, Atherosclerosis, Low testosterone, hormonal disorders and certain medications.

The erectile dysfunction can be treated by one of the followings:

Oral drugs like Viagra, Cialis, Levitra are useful if there is no associate heart disease or hypertension.
These drugs work by widening the blood vessels, causing the penis to become engorged with blood.
Another option is a medicated pellet that is inserted into the urethra and can trigger an erection within 10 minutes.

Vacuum devices for ED or pumps, offer an alternative to medication.
To use a pump, the penis is placed inside a cylinder. Then the pump draws air out of the cylinder to create a partial vacuum around the penis causing it to fill with blood, leading to an erection. An elastic band worn around the base of the penis is used to maintain the erection
Persistent ED, a penile implant can restore sexual function.
An inflatable implant uses two cylinders that are surgically placed inside the penis. When an erection is desired, the man uses a pump to fill the cylinders with pressurized fluid.

Psychotherapy can be beneficial for men with ED even when ED has a known physical cause. The therapist can instruct the man and his partner in techniques to reduce performance anxiety and improve intimacy.
Therapy can also help couples adjust to the use of vacuum devices and implants.

Hope this answers your query.
The suggestion given above could be useful in getting a proper treatment.

Wishing your husband a good health.

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