<s>[INST] Hello, Yesterday, I was rubbing my 5 year old son s back and then made my way up to the back of his neck.....On the right side of his neck, just above his collarbone, I felt a HARD, pea sized (maybe a little bigger) lump in his neck. He says it doesn t hurt. He has been feeling warm the past few weeks, but has NO signs of the flu. He just had blood work done 2 months ago, and his peditrician said he was as healthy as a horse, as a blood work was all normal. But, this was before I felt the lump. Is it something I should be worried about?? [/INST] Hi, The lump you have felt is most probably be an enlarged lymph node. The lymph nodes are part of lymphatic system in our body. The regional nodes get enlarged due to any infection in their area of Chat Doctor.  Since your child feels warm, he may be having a low grade fever also. I will recommend that you get in touch with your doctor for a repeat blood, a Contour test and a fine needle aspiration from the lymph node to confirm the infection if any. Take care. Hope I have answered your question. Let me know if I can assist you further.  </s>