Yes, there are.
The cases which exclude skydiving are the following:
Fracture within the past year, any accident involving articulatory or internal injuries or concussion, spine, heart and circulatory problems (high blood pressure), osteoporosis, epilepsy and any disease involving regular vertigo or fainting, seizure or convulsion. Skydiving is also excluded if the person is subject to any medical, mental or neurological treatment and (in case of ladies) if pregnant.
Each passenger has to fill in a declaration before skydiving in which he/she signs and thereby confirms that none of the above applies to him/her.
For other complaints not mentioned here, please contact your doctor and request a declaration of fitness to perform a tandem skydive.