Hello doctor, I am 26yrs old,female. have left anterior cervical , left preauricular and bilateral tonsilar lymph nodes palpable for 2 years and bilateral inguinal nodes palpable for a year and a half and able to palpate the submental node for past 6 months. they were never painful,all the size of a small peanut..my BMI is around 17.5 for the past 4 yrs .. ( am thin since childhood) what do i do?