I had a cold one mounth ago and it was finished after ten days.but why until now i feel a little itching in my chest and dry coughing occasionaly?

Habitual cough: Cough reflex is a vicious cycle, the more you cough, the more it gives you a tickle sensation in your throat. Take cough drops, cough suppressants and drink plenty of water. Try to suppress the need to clear your throat or start the first cough. Take a sip of water when you feels the tickle and go do something else.

Healing: It can take up to six weeks for healing to occur after viral bronchitis. Involves regrowth of mucosal lining.

Cough vs. allergies: A cough can persist even after the cold is finished. Also, you might have allergies or even asthma. You should discuss your symptoms with your primary care provider and decide together what the best treatment should be.

See your doctor: It may be only a residual of the cold, but you may have some asthmatic bronchitis as a residual from th cold.