Brief Answer:
Many causes

Detailed Answer:
Hello, I'm Dr. Branch, thanks for using Ask a Doctor. While there are many causes that could be responsible for your symptoms, especially if you had a history of dealing with anxiety, what you describe is suggestive of panic attacks. Panic attacks usually last several minutes to 1 hour, and patients often feel palpitations, sweating, trembling or shaking, shortness of breath, feelings of choking, chest pain, feeling dizzy, and often patients feel like they are going to die. If this describes how you feel during these episodes, it would be good to get in to see your doctor or a psychiatrist if you haven't already. This condition is often treated with antidepressants, benzodiazepines and psychotherapy as well.

There could be other causes for your symptoms, such as an abnormal heart rhythm or a problem with your thyroid, so it would be important to be evaluated by your doctor to get your heart and blood checked to make sure there's no physical cause for your symptoms.

Also, if you use a lot of caffeine, I would recommend that u-stop, is this could be making your symptoms worse.

I hope that helps, please let me know if you have any other questions or anything else you want me to explain further, I would be glad to do so.

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