My 18-year old daughter complains of terrible headaches regularly. Suddenly felt very feverish and flu-like symptoms this weekend, Also complains of pain and stiffness in back of neck and down into the muscles of her upper back. I know she s been sexually promiscuous. Also about 2 weeks ago, she had a swelling on her neck with flu-like symptoms again, all disappeared after a day or two. LOVES HIGH SALT/ SODIUM FOODS which we can t get her to stop with. Could she have HIV? She s very small and petite, otherwise, in good health.