Hi,Dear,
Thanks for the query to HCM.I studied your problem in depth and I understood your concerns.
Cause for the lump in your neck-In my opinion your description needs more clarification-as to -whether the lump is on the front side of the neck or sides of the neck.This is because your lump is not there as per your doctors.In my opinion-your lump-appears to be -a Engorged veins -as it comes after drinking lot of water?Check with your BP with your family doctor.
For Final Diagnosis and treatment needs clinical data from a Doctor.
Its not
thyroid as you think -otherwise Your doctors would have asked you to do USG and other tests to rule it out.
and Hence for further treatment I would advise you to Consult ER Surgeon , who would treat it accordingly.
This advise is based on the facts from the history you give and needs further clinical check.
Hence I would advise you to check with ER Surgeon.
So don't build up wrong concepts and create more psychic complications in you which would increase risks and costs to you.
Hope this would relieve your problem.
Welcome for any more query in this regard to HCM.
Write good resume and Click thanks if you feel satisfied with my advise.
Have a Good Day.
Dr.Savaskar M.N.