You might cringe at the thought of admitting that little vice you've managed to keep secret but you'd be crazy to keep it from your doctor if it is potentially harmful to your health.  

Your doctor deals with all kinds of crazy stories everyday - the fact that you smoke on the sly, have taken illegal drugs or occasionally have unprotected sex is hardly going to shock them.

"A doctor is not concerned about your behaviour: they are only concerned about your health," says Dr Ronald McCoy of the Royal Australian College of General Practitioners. So, next time you make a doctor's appointment, get ready to come clean about your lifestyle - and get the most out of your doctor's expertise.

Here are six common lies you really should avoid telling your doctor:

"Oh, I exercise regularly"

The number one lie we tell our doctors is that we're getting a good amount of exercise when we aren't. McCoy explains that not everyone is really aware of how much physical exercise they engage in, but that we all should be more conscious of this and make necessary adjustments to stay healthy.  

"I feel just fine"

When clearly you're not. You're at the doctor's rooms for a check-up, so spill the beans. That includes whether or not you are feeling depressed, lethargic, frustrated or helpless.  

Clinical psychologist Dr Darryl Cross explains that a GP should refer you to a psychologist if they suspect depression or anxiety which can crop up for a variety of health reasons.  

"I always use a condom"

Admitting the truth can be tough in this instance, but telling your doctor the truth could you’re your life.

No one wants to land themselves with a sexually transmitted disease, but if for some reason that does happen, your doctor will be able to treat you effectively.

All STIs can go undetected if you aren't tested.," warns sexual health physician Dr Katrina Allen.

"Many STIs have serious consequences such as sterility, liver cancer and skin diseases. They can be treated with antibiotics so identifying them is useful."

"I follow a balanced diet"

That is, if chips, chocolate and sugary drinks equal balanced… While it isn’t necessary to reveal each and every unhealthy treat you’ve enjoyed, it’s important to have a fairly good idea of your average daily diet.

Dietician Melanie McGrice emphasizes that the right food can have a really positive impact on your health and wellbeing, to the extent that you could even avoid medication through the right diet.

Going on a crash diet without seeking appropriate advice will also do no good – particularly if you have high blood pressure, high cholesterol or diabetes, warns McGrice.

"I'm not taking any other medication"

Keep a list of all medication and vitamins you ingest to show your doctor to make sure you don't leave anything out.

Your doctor will be able to make an informed decision about what medication to avoid giving you if they know that you are taking other stuff.

"I don't smoke… much"

Whether you light up every hour or just consider yourself a social smoker, your doctor needs to know.

Smoking can have a very serious impact on your health and will knowing you are smoking will help your doctor make the right calls when it comes to give you the best treatment possible.