We strongly advise that you take out travel insurance before embarking on your holiday. However you do not have to take the insurance offered by the first company you come across. It pays to shop around first!!
View the guide to Travel Insurance produced by the 
Association of British Insurers .

A travel company may charge as much as £40 per adult for a single trip whereas you can purchase an Annual travel policy covering several trips for the whole family from £50 upwards - but do compare the cover offered by different policies. Some budget versions exclude luggage, for example. Remember that travel insurance covers you for cancellation as well as medical expenses, lost baggage etc. and therefore an annual policy can be used to cover you for short breaks in the UK as well. 

For travellers with complex needs we recommend;

Travelbility Insurance

Tel: +44 (0) 1992 566919
Email: enquiries@travelbility.co.uk
Website: http://www.travelbility.co.uk

Dedicated travel insurance for the disabled and those with pre-existing medical conditions.

Offer cover whether you are disabled or able-bodied, travelling on your own, or as a group, couple or family.

Additional cover available for carers.
For single trip (age limit 79) or multiple trips (age limit 69).

If you are travelling within Europe or Worldwide.

The unique benefits of choosing Travelbility is cover for hire or replacement of mobility or disability equipment.

Replacement of essential medication if lost whilst away.

24/7 Medical Assistance with multi-lingual staff.
Loss of Baggage and Passport option.

******************

In order to qualify for the Spanish equivalent of the National Health Service remember to obtain the E111 form from a UK Post Office.

Goverment Health Advice