iam new to this forum iam 16 and i want to join the army but my dad has a history of ill health that runs in the family so there is a chance i might have the same complaints does your doctor have to tell the army
I wouldn't worry too much about hereditary illnesses. I stand to be corrected, but they usually signify an increased risk of catching the disease, rather than a certainty. Most illnesses can still be caught by people who don't have a family history of it.
Besides, you may be lucky and one day find that your dad is just a bloke who didn't have a viable alibi.
As puttees said, essentially it only indicates a predeliction for an ailment and you didn't actually state what it was. If it's galloping knob-rot, you'll be in good company in the army.
If it's nothing too dramatic and you're aware of it at this comparatively early stage in your life, steps can be taken to avoid it, or at least to mitigate the effects on you health.
The best thing to do would be to get some gen off your doc (including an opinion of any likelihood of it affecting you), see what you can turn up on t'internet on your particular ailment(s) and get down to the AIC to see what they say about it.