<s>[INST] My 19 month old daughter keeps getting blue lips, finger nails and toenails in the morning. Recently she became ill with a fever for 5 days. When I took her in to the doctor they noted that her oxygen levels were very low but could not come up with an explanation. What could be going on with my child? [/INST] Hello,A low oxygen level, blue lips and fingers can be seen in cyanotic heart disease, but manifestations of heart disease are seen early in life. Though still needs a chest x-ray, 2 d Echocardiography to rule out same.Hope I have answered your query. Let me know if I can assist you further.Regards,Dr. Sachin Kumar Agarwal </s>