Millions of people in the UK struggle to get travel insurance every year on account of their pre-existing medical conditions. Others end up paying through the nose for it.
Those with health problems, or even those who hadissues in the past, are deemed morerisky for an insurance company to coverand so are more likely to need treatment while abroad, which the insurer will need to foot the bill for.
This can drive up the cost of insurance and may mean that those looking for coverneed to get it from a specialist provider.
One in five people can't get travel insurance because of a historical health problem, according to a recent study by Co-op.
Mintel, the market research firm, said4.2m people had difficulty getting cover in the past three years, because of a previous diagnosis.
Below we've listed what kind of factors impact price and the providers who offerthe cheapest cover.
For example, holidaymakersin their 20s taking medication for high blood pressure will find it easier to get cheaper travel insurance than someone over the age of80 with the same condition.
Regardless of how common or manageable you think your condition is, Stephanie Corbett, head of travel at Comparethemarket.com, the comparison site, said it is important to always be honest with the provider when buying travel insurance as "failure to do so may mean you're underinsured or your policy voided".
How old are you?
The older you are, the more risky you are to cover, meaning costs will rise.
For example, the cheapest cover for someone aged 20 with high blood pressure taking one type of medicine,travelling worldwide for a week, costs £15.33 from Insuratrip, according to comparethemarket.com.
The same person could get a week's cover in Europe from Puffin for £4.98.
But once you get to 80 years old, you can expect to pay five or sixtimes as much with the same medical condition.
A week's worldwide cover would cost £74.66 at the lower end from Insuratrip, which is the cheapest by far. Saga and Insuratrip, which are both top five providers in this instance, offer insurance for £132.59 and £139.94 respectively.
The cheapest insurance for a week in Europe for the 80-year-oldcomes from Just Travel and costs £29.60 - almost six times as much as the 20-year-old.
Where are you going?
You can expect to pay far more for travel insurance if you're travelling outside of Europe because medical care is considered more costly. And if you've got a pre-existing condition, insurers see you as more of a risk.
If you need emergency treatment in America, Canada and the Caribbean, it can be eye-wateringly expensive.
For example, last year a British woman Denise Griggi, 63, was trapped in San Diego, California, unable to paymedical fees of £200,000.Doctors said she was too ill to travel on a normal flight and needed an air ambulance to get her back to Britain.
The cost varies but a quote for a 20-year-old woman diagnosed withbreast cancer two years previously undertaking chemotherapyshowed premiums fromYour Travel Cover would be£12.25 when travelling in Europe for a week.
This was almost four times higher for the same woman travelling outside Europe, costing£46.02from insurer Travel Time.
The cheapest insurance for a woman of 80 with the same condition jumped from £73.44for a week's cover in Europe, from Fit2Travel, to £278.20for worldwide insurance from Saga Select.
What condition do you have – and how bad is it?
Insurers will take into account a wide range of factors relating to your medical condition including any medicine you might be taking, hospital visits and whether or not you smoke. All of these details will impact how much you pay.
For example, we looked at two quotes for a 20-year-old with asthmalooking for travel insurance for a week long trip to Europe.
If they had not been hospitalised because of the condition, were taking up to two medications, were a non-smoker and were not on oxygen, the cheapest cover for a week in Europe was £4.98from Puffin Insurance.
However, someone the same age with more severe asthma could expect to pay almost 13 times as much.
An individual of the same age who has had one hospital admission because of asthma, takes three to five medicines for their condition and smokes could find insurance for£64.35from Fit2Travel, a specialist provider, at the lowest end.
The cheapest insurance for a 60-year-old with the more moderate asthma is £8.31 from Puffin. This leaps to £77.39, provided by Admiral, for the more serious condition.
Which providers will insure me if I'm elderly or have a serious health condition?
TheAssociation of British Insurers, an industry group representinginsurance firms, advised those with long term and serious health conditions, such as cancer,to use a specialist provider.
The British Insurance Brokers Association, another industry group, is also worth trying as they work with a number of brokers.
Specialist insurers or brokers that focus on older people or those with pre-existing conditions may offer more comprehensive cover. Such providers include Staysure, Avanti and All Clear Travel. See here for a list ofothers.
Insurers appear to be looking closely at this market and anumber of new insurance offerings have been launched this year.
In January Co-op and Bought By Many both introduced cover for travellers that might struggle to get it elsewhere because of their age or health.
Co-op's travel insurance has no upper age limit, although if you're older than 90 you'll need to call it first. But single-trip insurance for over 65s is limited to 31 days.
If you get ill on holiday, it will pay the hospital directly instead of you paying and claiming it back on your return, which is usually how insurers work.
Co-op customers also get 24/7 access to a doctor in the UK before and after they travel. You can call the doctor at any time and video-call appointments are available between 8am and 10pm.
Bought By Many offers urgent medical travel insurance for people with serious health problems. There is no medical questionnaire, instead the firm contacts your GP to find out if you're well enough to travel. There is also no upper age limit.
But there are limits. Bought for Many covers emergency care for travel in Europe. And you'll need to have a valid EHIC card. Those with a terminal prognosis of under six months will not be covered. Bags and cancellations are also excluded.
Be cautious whenusing comparison sites if you have long-term or serious health issues.
A recent study by City watchdog the Financial Conduct Authorityfound that peoplewith long-term illnesses are paying up to fourtimes as much for insurancewith some popularcomparison sites because their illnesses are deemed"non-standard risk" and not included in searches.
But before you opt for the cheapest travel insurance, check what's covered.
Remember your EHIC card - but it should not replace travel insurance
A European Health Insurance Card (EHIC) gives you the right to treatment in state-run hospitals in EU countries, those in the European Economic Area (Iceland, Norway and Liechtenstein) and Switzerland.
Armed with this free card,you're entitled to medical care in the same way as a resident would be, either at a reduced cost or for free.
The EHIC covers the treatment ofpre-existing medical conditions and routine maternity care.
However, it should not be used instead of travel insurance. It's not valid on cruises and it won't cover private medical costs or if you need to be flown back to the UK.
Don't be fooled by the number of unofficial EHIC sites that charge for the card - you can apply for it herefor free.
Reader Service: Do you know what medical conditions you need to declare when you buy travel insurance? Discover more about the Telegraph Media Group Travel Insurance Service.
