Anyone with any pre-existing psychiatric conditions will NOT receive medical clearance and will have their offer rescinded. Saudi Arabia does NOT issue work visa/Iqamas for expats with pre-existing psychiatric conditions.
Furthermore, anyone who tests positive for Hep A, B, C, Cholera, Malaria, Syphilis, HIV/AIDS, and TB, will be deemed unfit and NOT receive medical clearance.
Also, varicose veins can be an issue, given the weather conditions and walking that is required.
Basically, all candidates should be reasonable fit, being overweight or obese is fine, however, usually both come with additional health conditions, hence, the medical examination.
Existing conditions such as Cholesterol, Diabetes, etc, that are managed with medical documentation are acceptable.