robdob - yup - thats about right - we are getting into areas with no definition. I would doubt HR would have standard defintions
Myself I would have thought cancer, diabetes and similar would come under disability discrimination but it ain't clear. I would doubt the OP would fall under disability discrimination for this
TUC take on it
Am I allowed time off work to see my doctor?
There isn't a general legal requirement for your employer to give time off for medical appointments. Whatever entitlement you have to time off to visit the doctor will be governed by your individual employment contract.
You should check your contract and staff handbook, as this may specify what the regulations are in your workplace. Some employers may require you to take annual leave, or take the time unpaid. On the other hand, many employers will be flexible on this, and it may be worth asking your employer if you can make up the time later.
If you have a disability which requires you to make regular medical visits, then the Disability Discrimination Act (soon to be consolidated within the Equality Act) may also apply here. This states that employers need to make 'reasonable adjustments' to prevent disadvantage to disabled employees. 'Reasonable adjustments' are not well defined in relation to this issue (so it would be a good idea to seek individual legal advice from your union or solicitor), but they could include greater flexibility in your hours to cover gaps, or availability of time off (paid or unpaid) when needed.