You are probably wondering ... so here is the answer.
Those of you who have never dived before may wonder if a medical examination is mandatory. The answer is no, at least not always but ...
I say not always because it can depend on the course you are taking, where you are and how how general health fitness.
In the PADI system, you will not need it until Divemaster level. The certifications before that (PADI Open Water, PADI Advanced, PADI Rescue) as well as the specialties are made on the basis of a declaration by the candidate. This is a questionnaire called "Diver medical - Participant questionnaire". You must declare there any physical problems you may have. Depending on your answers, it may be inappropriate to dive or a medical certificate may be required. Do not be afraid, it is - generally - quite rare that a medical examination is necessary. But please be honest and dont "cheat" just to avoid a medical examination.
I do not know all the local regulations but I would not be surprised that in some cases medical advice is mandatory, I am thinking here of certain countries with more stringent standards (USA or EU). I did all my courses in Thailand, it was never compulsory before the Divemaster.
If you have any country specific information please let me know and I will share it on the site.
Either way, answer the questionnaire honestly ok. Don't take a risk just to be cool with your friends and be able to tell your girlfriend or wife that you are the new Indian Jones of the oceans. If a medical advice is advised, do so. Also for insurance reasons. As you know, insurers will not compensate you in case of false declaration or misrepresentation.
Obligation vs comfort
The fact that it is not mandatory does not prevent you from visiting a sports doctor or even your general practitioner before you try diving. It is quite respectable to feel a little feverish before you try and seek expert advice.
I myself had seen a doctor not for diving but for my only parachute jump ... in fact I was really scared and looking for an excuse not to jump (it was a birthday present. ..thanks Patrick, I still remember) but the doctor said I was ready to jump off the plane.
In general, this will be limited to checking your general condition, your breathing, your ears (due to the pressure undergone underwater) and any contraindications or limitations (cardiac subject, ulcers, epilepsy and others. ). Be careful, I am not saying that this will prevent you from diving, but it is good to have a general view of the possible risks.
Some elements of the physical examination
I am not a doctor and I do not pretend to tell you here what is important or not. I simply draw your attention to a few elements that will be taken into account, among others.
Did I manage to scare you? Perfect. Now relax. I will not go into the details of each of these groups. Firstly because I am incapable to do so. Second, because the goal is not to scare you but simply to educate yourself a little. A skilled diver is worth two.
All this to tell you that the physiological aspects of diving have been studied for decades and that many potential problems can be identified early. Which, in turn, should give you confidence.
For those interested, the details of these systems are available on the PADI questionnaire mentioned above.
The Diving Bear