hello, welcome to healthcaremagic.com stress can cause somatic symptoms like heaviness in hands, head, limbs, difficulty to speak as well. usually our mind try to cope up with different stress through different mechanisms, however during stress overload when over conscious mind fails to control the stress, our unconscious mind comes into play. in order to seek support from external environment, our unconscious mind do illicit some physical or mental symptoms of which we are unaware of, in order to relieve the conscious mind. as you mentioned your exams are near by, your are under stress, hence to cope up with your stress, your unconscious mind may developed this symptom. i would advice you to relax your self. try to maintain your sleep hygiene, sleep well for 6-8 hours, eat healthy, have healthy interaction with family and friends as well and dont let the exam worry catch you. further query in future do followup with me.