It seems that many people in the UK ask themselves this question and conclude that there isn't a reason to take out travel insurance. For a very few this may actually be the right conclusion, mainly those with enough money to cover any costs they may face, but for the vast majority of us, travel insurance provides necessary safeguards against mishap on our journeys, whether for business or pleasure.

Below I will detail some reasons, but by no means all, for having a travel insurance policy and possible consequences of not having one, but as everyone is different it is incumbent upon each person to make an assessment of their own needs in deciding whether they need to buy a travel insurance policy or not.

The major expense you may face when abroad is the cost of emergency medical treatment, please note the word emergency as travel insurance does not cover routine medical treatment or any treatment that the insurer considers could have waited until you return to the UK.
It does include the cost of transport to a hospital for emergency medical treatment, such as an ambulance, as in many countries the ambulance service is provided by private companies who charge for the service.
Most travel insurance policies also provide for repatriation to the UK once the attending doctors consider the patient fit enough to travel and this can include the costs of a doctor or nurse to be flown out to travel with the patient on the return journey where necessary.
It should be noted, however, that most travel insurance policies require you to notify the insurer as soon as possible if any treatment to be received is likely to cost above a set figure, and this figure can be as low as ?250, in order to get the treatment authorised, failure to notify the insurer may invalidate any claim, so you must read the policy documents and familiarise yourself with the claims procedure. This is why it is vital to have a copy of the travel insurance policy and documents with you when you travel. Always err on the side of caution and call the insurer's claim handling number if you are unsure.

The range of cover available for emergency medical treatment included on a travel insurance policy is often within the range of ?1 million to ?10 million.

Most travel insurance policies include some cover for emergency dental treatment but often this is for no more than a few hundred pounds and usually only for treatment to stop pain, not for any remedial work.

Most travel insurance policies, and especially the cheaper ones, do not cover pre-existing medical conditions, mainly because the costs to the insurers for claims by people without pre-existing medical conditions are significantly lower and, therefore, the insurers can keep the premiums down.

If you have pre-existing medical conditions you have a choice to make, namely do you buy a travel insurance policy that will cover emergency medical costs arising from an episode that can be attributed, either directly or indirectly, to the pre-existing medical condition or not.
Bear in mind that you will only be covered on a travel insurance policy for costs of medical treatment that require immediate attention, so you have to decide if your condition(s) is/are the type of thing that could flare up suddenly and require you to need emergency medical attention and I would suggest that you discuss this with your GP if you haven't already.
It is not mandatory to declare a pre-existing medical condition to an insurer and pay the extra cost to have it covered, but if you choose not to you must accept that the insurer will reject any claim for costs associated with the condition and not just the medical costs.
There are definitely some medical conditions that I would consider it to be unwise not to cover, these are mainly systemic conditions such as high blood pressure and diabetes; any heart related condition; any stroke related condition; cancers if there is a possibility of a sudden deterioration in health or if the cancer may spread to other parts of the body; any condition that may cause loss of balance, such as epilepsy, which could lead to a fall causing sprains or broken bones; and any condition that can cause a sudden episode that requires immediate treatment by a medical professional, such as gall stones where the gall bladder was not removed.
This is not a comprehensive list by any means, only you and your doctor(s) can make the necessary assessment of the likelihood of an occurrence triggered by a pre-existing medical condition.

After cover for emergency medical treatment the next largest sum insured on a travel insurance policy is normally personal liability cover which is cover in case you are responsible for damaging someone or their property, although it is usual for any damage caused by you operating a vehicle or an animal under your control to be excluded, a separate policy in these circumstances is required, although if you are renting the vehicle or animal, the required insurance may be included in the package and you should check that this is the case. Cover for personal liability is usually between ?500,000 and ?2 million.

If you become involved in litigation as a result of an incident on your trip you will be thankful for the legal expenses cover included in most travel insurance policies, although this is usually no more than a few tens of thousands of pounds rather than the much larger sums for emergency medical treatment and personal liability, how many of us have that much spare cash available?

Other parts of a travel insurance policy include cancellation cover, personal belongings cover, cover for loss of money or passport, and cover for travel delay or disruption, although this is normally only for the initial travel from and returning to the home country, any connecting flights or other transport are not covered. While these incidents are no doubt irritating and inconveniencing they are not potentially financially ruinous.

In summary, unless you can cover all the potential costs of an incident abroad with your existing financial resources, and even then, who would want to use up those resources instead of spending a tiny fraction of them on a travel insurance policy, it makes sense to buy a travel insurance policy.
Without travel insurance you would be forced into making the decision of whether you can afford potentially life saving medical treatment or not, a most invidious position in which to find yourself.
As with all forms of insurance you have to balance the cost of the policy at the outset against the potential cost of not being insured.
My intention here is not to give advice but to raise topics you might want to think about, in the end only you can make the assessment about what is right for your circumstances.
Whatever you decide I hope you have a happy and trouble free trip.