Exclusive: Howard Gorrell's Sydney property is so heavily infested with ticks that a doctor urged him to sell up and move.

Gorrell said he gets viciously attacked and bitten, sometimes by up to 100 ticks at a time, whenever he goes outside to enjoy his tree-lined, one-acre plot in Glenhaven, which is located in The Hills District.

The 76-year-old grandfather said the attacks have ramped up since massive rains smashed Sydney in late summer last year, combined with changes to local bylaws which have made it more difficult to burn mulch, an environment where ticks can prosper.

Adding to his frustration and discomfort, Gorrell said many GPs and hospital doctors have misdiagnosed the severe reactions that parasite bites trigger in him, and that many medical practitioners do not properly understand the problem.

Gorrell said he can be struck with body aches and bouts of dizziness, and even suffers heart palpitations which have concerned his cardiologist.

"It's terrible," the retired automotive salesman told 9news.com.au, describing the intense, uncontrollable itching and large red patches that break out on his body after the ticks inject potent neuro-toxins into his bloodstream.

"They (the ticks) could be used for torture treatment."

Ranging in size from a tiny dot to the head of a match, Gorrell said he often doesn't know there's a tick on his body, inserting sharp barbs into his skin to feed on blood, until it's too late.

"It normally takes a couple of days before you realise," he said.

"They're just a little black speck, like a full-stop from a pen.

"And if you don't realise what they are, you start scratching them and then the itch sets in and usually lasts a couple of weeks, even if you get rid of them.

"It's just unbelievable. It drives you crazy."

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