Over the past 2 days, I have felt as though a thin chain is tightening around my neck, midway between my chin & the base of my neck. Also, this morning, I noticed an indented dark line at approximately the place I am feeling the pressure. I am 73 years of age & while I have wrinkles around my neck, I have not noticed this distinct line before. If I stretch my neck upwards, the pressure leaves. Can you give me any insight into what may be causing this pressure on my throat. Thank you.