I had my first panic attack after smoking cannabis. I experienced chest pain, shortness of breath and bad shaking. I returned to work about a week after Christmas and felt completely fine, finished my shift and got home. I got into bed at around 2.30am and settled down. After about ten minutes I felt a dull, kind of pressing feeling in the sternum area, right in the center. It was not painful just nagging and quite heavy. Immediately it worried me so I got out of bed and watched tv for about half an hour then returned to bed but it didn't stop. At the time, I had no other symptoms like breathlessness or dizziness just the sternum discomfort. It also seemed to be relieved by burping. I looked online for symptoms which told me heart attack. This made me instantly panic and I began to violently shake, my mouth was very dry and I felt absolutely helpless. Burping seemed to ease it but not completely. An NHS nurse urged me to call an ambulance which I did. When the ambulance arrived they performed an ECG or EKG which showed no signs of heart problems but decided to take me into hospital just to check me over. Another ECG was performed and a nurse checked my pulse. I was released after 4 hours after being told I was completely fine. I then worried almost constantly about my heart, thinking that they missed something. I began getting more anxiety attack symptoms and felt like I was being smothered, lightheadedness, fatigue, problems sleeping, derealization etc. Blood test showed normal except Thyroid. I was told that it was only slightly abnormal and that the doctor did not need to see me about it. I have also suffered from muscle tightness, constipation and diarrhoea, stomach bloating, indigestion and lightheadedness. Luckily, the severity of the attacks has decreased but I am left more with general anxiety I believe. I am just wondering if it is indigestion or something similar.