My son was running in a cross country event when he started to have problems with his asthma. (This does not happen very often.) He completed his race and then used his inhaler. It took awhile to work and  his right hand began to cramp up and feel numb. His hand was not cold and when we pressed his fingernail it turned red quickly showing that there was blood reaching his fingers. After his breathing was under control the feeling began to come back into his hand and it uncramped. What could of caused this?
Hi, Asthma problem may be the cause for his numbness and cramp due to decreased oxygen supply. Usually before any exercise or sports better to give one puff of inhalation Chat Doctor.  This will prevent his symptoms to appear.  Sports or activity may act as a trigger for asthma attack. Daily montelukast will also help in preventing exercise induced asthma. Hope this helps you. Feel free to ask for any further queries. Regards