Nearly 15 years ago I suddenly developed constant pulsatile tinnitus (a whooshing sound in sync with my heartbeat) in my left ear. Many tests have failed to find the cause. But I’ve recently discovered that my platelet count has been low at every annual health review since 2012. Could there be a connection?

Name and address supplied.

Dr Martin Scurr replies: Pulsatile tinnitus is where you hear certain sounds much louder than normal, such as your pulse and heartbeat, and is usually caused by a neurological or vascular abnormality – effectively, you’re hearing your blood flow.

I think it very unlikely your low platelet count is to blame.

Platelets are specialised cells in the bloodstream that play a key role in blood clotting.

A low count is referred to as thrombocytopenia. This can be caused by a number of conditions, including rheumatoid arthritis and liver disease.

But your tests have come back clear – and it may be that you have always been someone with a low platelet count but remain otherwise healthy.

Pulsatile tinnitus is typically caused by abnormalities in the blood flow near the ear – such as high blood pressure – or a blockage in the main arteries in the neck or an aneurysm (a bulging blood vessel, possibly as a result of age).

Again, tests would appear to have ruled out a cardiovascular link. I hope that this brings you some reassurance.

In terms of what might help, I would ask your GP for a referral to a specialist: one option might be a ‘masking’ device – worn a bit like a hearing aid, this provides a constant background sound that helps reduce the perceived loudness and intrusiveness of the tinnitus noise.

Over time, you should feel less aware of it and, eventually, learn to ignore it.

I recently had a bad toothache and saw a dentist, who prescribed a five-day course of amoxicillin (which I’ve had before with no problems). Within ten minutes of the first dose I went bright red, developed lumps all over my body and started struggling for breath. Paramedics gave me adrenaline and I was rushed into resus. A month later my face keeps getting red and hot and my breathing isn’t back to what it was.

Bonni Montague, by email.

Dr Martin Scurr replies: I think that, on the ­balance of probability, the amoxicillin – an antibiotic in the penicillin family of drugs – was responsible for your frightening episode.

The facial flushing and breathing difficulty following an anaphylactic attack can often persist for up to three days following treatment (although occasionally, when a reaction is severe, such symptoms may persist for weeks, or longer).

The question must be: why would you develop an allergy to a penicillin now?

Essentially, previous courses earlier in life have primed your immune system to produce IgE antibodies – key molecules that help fight infections and allergies – in response to penicillin.

And now your allergy has reached tipping point.

This is not uncommon in ­people later in life to ‘suddenly’ become allergic to a drug in this way.

Now that this has occurred, the only way to avoid future ­similar events is to avoid all contact with any penicillin-related drug. This is a lifelong allergy.

Given how difficult it is for most patients to see a GP, let alone see the same GP for continuity of care, it doesn’t surprise me to hear that a number of organisations now offer to carry out a wide spectrum of blood tests for a fee. And that people are taking this up.

The problem with self-referring for a barrage of blood tests is understanding the implications.

Someone at a company where I am the medical advisor came to see me recently with 66 pages of results for such tests.

Most of the tests were irrelevant, but there were enough red flags – where his results were outside the ‘normal range’ – to make this man think that, despite feeling well, he might be seriously ill.

But the ‘normal range’ on tests mostly only indicates where you are on a spectrum, not whether you’re unwell.

Interpreting results depends upon the patient history and circumstances – relying on tests as the first line of action is merely pouring petrol on to an already smouldering fire of anxiety.

It would be better to pay to see a doctor than pay for tests you’ve decided on yourself.