Dear thanks for the question. Ideally you should have mentioned your age and height for weight related questions. Although your weight is not very high but in the manner it is increasing is really worrisome. If I were your family doctor I would have inquired about the food intake and change in any routine of your activities. According to me it is related to diet and exercises. You need to control your diet and start physical activities. However the possibility of sudden hypothyroidism (reduced thyroid function) is also there (remote chances). I would like to advise you to look in to these aspects and consult doctor if you are not able to know the reasons and able to stop this rapid weight gain. I hope i have clarified your queries. Do write for follow up queries. Please rate my reply. I wish you success in your efforts. Thank you.