Welcome to JA and thanks for this question. Im sorry to hear about your friends symptoms. Now from what you are describing it sounds like that your friend may be suffering from a condition which is known as arrhythmias. this is a condition in which the heart can beat irregularly at time and can speed up or even slow down at times. This can occur because of a number of causes including heart disease such as blockage of the coronary arteries. In severe cases this can cause symptoms like palpitations, shortness of breath, chest pain, sweating, dizziness, lightheadedness, weakness, numbness in the limbs. This would need to be diagnosed with the help of a simple EKG and if necessary a 24 hour holter monitor which monitors the heart continuously for a full day. In additiona echocardiography should also be done in this case. This can also be due to hormonal issues including thyroid problems or even cortisol issues. Electrolyte imbalances and dehydration can cause this as well.
Another cause can be sick sinus syndrome in which the heart sends out abnormal signals leading to either very low heart rates or very high ones, this again wouild be diagnosed in much the same manner as above and would be treated with a pacemaker. Whereas arrhythmias are usually treated with medications.
Now i would recommend that you take your friend to the doctor and get these tests done as these abnormal heart rhythms can be dangerous in some cases.
Do you have any more questions?
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