In a series on celebrities and their health, the BBC News website talks to racing driver Sir Stirling Moss about his erectile dysfunction.
Stirling Moss was diagnosed with prostate cancer
Sir Stirling, 76, started racing at the age of 18 and soon made his name in Formula One, Two, Three and hill climbs, sports and touring car races as well as rallies and world speed record events.
An accident at the Goodwood track in 1962 left him partially paralysed for six months and ended his Grand Prix career, although he continued to race historic cars.
Sir Stirling, a spokesman for SortED in 10, the education campaign sponsored by drug's manaufacturers Bayer, (makers of Levitra) was given an OBE in 1959 and knighted in 2000.
HOW DID YOU FIRST REALISE SOMETHING WAS WRONG?
I have had this problem twice. The first time was after I had a crash in 1962 and was in a coma for four weeks.
I had a very attractive nurse and I turned to her and said, 'I would love to do something about this but I can't'.
Talking to her about it helped me through it.
The second time was when my prostate was taken out when I had cancer at 70. They cut it out and said I might have a problem with an erection.
My wife, Susie, and I are very close though and we fought the problem together.
HOW DID YOU GET DIAGNOSED?
I was diagnosed in a clinic in America, the Mayo Clinic, when I went for a complete check-up.
They found I had prostate cancer.
They took 12 tissue samples and four of them were cancerous.
WHAT WAS YOUR REACTION TO THE DIAGNOSIS?
I said I wanted the cancer out. They gave me three options, but I said I just wanted an operation and I wanted it straight away.
I think if you have cancer and they can cut it out then do it.
I just felt 'lets get rid of it'.
WHAT WAS YOUR TREATMENT?
My prostate was removed. Then I just took it easy.
As for the erectile dysfunction when I got that far ahead, because I did not realise straight away that there was a problem, I said to the doctor that I had a problem and he told me the options.
The impotence drug Viagra did not help me and I found an alternative called Cialis did not have very quick results, but a drug called Levitra suited my lifestyle. I took it and within 15 minutes I could be 'in action'.
If you take one of these drugs you do not get an erection immediately.
HOW DID YOU FEEL DURING TREATMENT?
When I was in hospital getting treated for the prostate cancer I felt knocked out - it took quite a lot out of me.
This might have had something to do with the fact I had just turned 70 when I found I had cancer.
With the erectile dysfunction I felt frustrated when the treatment did not work and then elated when it did.
When you are with a person you know so well and are close to you can really feel the urge (for sex) and if you have erectile dysfunction you can not do anything about it.
You can feel really amorous and really horny but if you don't get an erection your partner will not know anything about how you are feeling.
It is amazing how many people suffer from it. I think the government should give more funding to addressing this problem.
The biggest problem is that men will not come forward. Men worry that admitting they have the problem will reflect on their masculinity, but it has nothing to do with masculinity.
One in three men suffer from this and if they have got this problem they should go to their doctor and if they have got a partner they should go with them to see the doctor. It should be a shared problem.
HOW DO YOU FEEL NOW?
Now I just feel that is a bit annoying that I have to take a pill to 'get it up'.
It is much more exciting for it to happen naturally, which is a lovely thing.
WHAT IS YOUR MESSAGE TO OTHER PEOPLE WITH THE SAME CONDITION?
The message to anybody is go and see the doctor - they can help and do help.
If you have a partner take them with you. You have got to share it.
You can't think it will just get better. There are a lot of things that could be the cause - things like diabetes you should get it checked out.