Students who have a disability or chronic illness can apply for compensation for disadvantages according to Section 11 of the Framework Regulations for Degree Programs and Examinations.
This includes students who have chronic physical illnesses, mental illnesses, neurodevelopmental disorders such as dyslexia and attention deficit hyperactivity disorder (ADHD), sensory disorders, and mobility issues.

This definition of disability is in line with Section 2 of the Book IX of the German Social Code German and Federal Act on Participation (Bundesteilhabegesetz). You do not have to have a severe disability to apply, but you will not be able to get compensation for disadvantages if you have an acute (short-term) illness that results in you being unable to take an examination. You can find further information under Legal Matters.