Bella Hadid's 'invisible suffering': What causes Lyme disease and how is it treated?

Model Bella Hadid has opened up to her 53.9 million Instagram followers about her "almost 15 years of invisible suffering" with Lyme disease.

The US-based 26-year-old wrote, alongside snippets of her unwell and in hospital, about her battle with the chronic illness: "Living in this state, worsening myself with time and work while trying to make myself, my family and the people who support me, proud, had taken a toll on me in ways I can't really explain."

"To be that sad and sick with the most blessings/privilege/opportunity/love around me was quite possibly the most confusing thing ever."Lyme disease, a bacterial infection, can spread to humans if they are bitten by an infected tick.

What are the symptoms?

Many people with early symptoms of Lyme disease develop a circular red skin rash around a tick bite, often described as looking like a bullseye on a dart board.

The rash can appear up to three months after being bitten and usually lasts for several weeks.

Most rashes appear within the first four weeks after being bitten.

Not everyone will get a rash, and some will experience flu-like symptoms in the early stages, such as a high temperature, or feeling hot and shivery, as well as headaches, muscle and joint pain, tiredness and loss of energy.

But symptoms of chronic Lyme disease, or Post Treatment Lyme Disease Syndrome (PTLDS), can persist long after treatment and cause profound fatigue, pain in the joints and muscles, or cognitive impairment.

An Instagram snapshot of Hadid's medical record when she was 17 reads: "She is extremely exhausted and depressed and does not attend school anymore... She feels ill all the time and has memory problems."

How is it diagnosed and treated?

Anyone who thinks they may have Lyme disease should visit their GP, who can carry out two types of blood test to help confirm or rule it out.

If confirmed, patients will be prescribed a three-week course of antibiotics.

Most people will get better, although this can take several months.

For those that continue to have symptoms, they could last several years.

What precautions can be taken to prevent it?

The South of England and the Scottish Highlands have been earmarked as high risk areas for Lyme disease.

Exmoor, the New Forest and other rural areas of Hampshire, the South Downs, parts of Wiltshire and Berkshire, parts of Surrey and West Sussex, Thetford Forest in Norfolk, the Lake District, the North York Moors and the Scottish Highlands are all known to have a particularly high population of ticks.

Covering up bare skin while walking outdoors, using insect repellent, staying on paths whenever possible, and wearing light-coloured clothing so ticks are easier to spot and brush off are all ways to reduce the risk of being bitten.

How common is it?

It is estimated there are 2,000 to 3,000 new cases of Lyme disease in England and Wales each year.

Researchers from the UK and Germany looked at a primary care database holding anonymised records of 8.4 million people registered with GP practices between 2001 and 2012 – about 8% of the general population.

Some 4,083 cases of Lyme disease were detected among 4,025 patients.

Of these, 1,702 (41.7%) had “clinically diagnosed” Lyme disease, 1,913 (46.9%) had “treated suspected” Lyme disease, and 468 (11.5%) had “treated possible” Lyme disease.

They found the annual total number of cases recorded increased almost ten-fold over the period, from 60 to 595, suggesting a UK estimate of 7,738 cases in 2012.

If the numbers continued to increase post-2012 at a similar rate, they believe the UK could see an excess of 8,000 cases this year.

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