Pea sized Knot and no erection

I have noticed lately that my husband's erections have been little to nothing.  Last night he could not even obtain one.  After laying there for awhile we felt an abnormality in his left testicle that felt like a little knot attatched to what I assume is his tubes inside his left testicle.  Does this make sense.  He is only 38, and I guess I understand his erections at some point are not going to be what they always have been, but I am concerned if there is a problem.  I asked him this morning if he was going to get it checked out and he said no he just thinks it has always been there and he just never noticed.  The knot seems kinda hard and soft, it's hard to explain, and it seems to move around, but always attached to the tubes.  Am I making any sense?  Is this normal?

Thank you!

[Kevin Pho, MD]

Hello - thanks for asking your question.

There are many causes for male impotence.  The evaluation should be undertaken in conjunction with your personal physician.

Psychological and emotional factors - Depression, performance anxiety, and lack of sensate focus are readily identifiable psychologic causes of impotence.

Hormonal abnormalities - Testosterone deficiency causes impotence and is corrected with testosterone treatment.

Autonomic neuropathy