<human>: Hi, ever since I was a teen when playing tennis, i would go to hit the ball as hard as possible and occasionally I would get a shock to the back of my head and collapse to the ground. straight after I am fine and continue playing. yesterday in the gym lifting a weight the same thing happened for the first time in about a year
<bot>: Hi, Thank you for posting your query. You would need detailed evaluation to find out the cause of your symptoms. Most importantly, you need an MRI scan of brain with crania-vertebral junction, to exclude any anomaly there. In addition, a carotid Doppler should be done to ensure that the blood vessels to your brain are normal. Please consult a neurologist for detailed evaluation. There is no need to worry, as you would get better with treatment. I hope my answer helps. Please get back if you have any follow-up queries or if you require any additional information. Wishing you good health, Chat Doctor. Ly/