No need to worry. At this age it happens when sexual desires which remain undesired, cause such things. Excess seminal fluid and semen are released through nocturnal emissions. Some people get it released through sexual act or masturbation. But if these nightfalls are in excess then my patients are advised to take Ayurveda s Chanderprabha vati and Gokshur guggul. These are commonly available in India. Elsewhere pl get online. Some lifestyle changes like urinating before going to bed, avoid cold drinks, avoid stimulant food and movies etc. Better to meditate for few minutes before sleeping. Hope it helps.