I have a lump on the left size of my neck in the back of my neck. it doesn't hurt but it just worry me. help please!

Lump: Monitor its size and character. Is it tender or red? if so, see a doctor. Is it growing? if so, see a doctor. It may be a simple cyst. This is harmless. Track it.

Prob lymph node: If you are otherwise healthy, it's probably a lymph node. Check to see if you have any irritation in the area above the lump? in your scalp also. If it gets bigger or doesn't go away in a week to 12 days, always good to have it checked by your doctor. Don't worry and I'm glad you wrote in.

Neck mass: You are describing a non-tender poster neck mass. If its truly on the back of your neck, most likely may be an epidermoid cyst or an enlarged lymph node. The differential diagnosis of anterior and lateral neck masses is long and complex. You need to be seen by an ENT for a thorough exam, possibly imaging and/or biopsy.

Please: have it examined. could be a cyst or lipoma or lymph node or lymphoma

Lump: Most likely in that area it may be a lymph node - have your primary physician evaluate it to make sure it is not more serious if it gets bigger or changes in any way.