Anyone who needs some form of care should get a care assessment, known as a Section 47 assessment. This enables the local authority to decide the level of care needed.
You can then get your finances assessed to see if you're eligible for support with costs. Occasionally, local authorities try to dissuade people from getting a Section 47 assessment on the basis that they won't be eligible for funding anyway - but a Section 47 is everyone's statutory right, and you should insist.
To get your Section 47 assessment, the first thing to do is to contact the local authority services. They will organise a home visit and maybe a chat with the GP.
The assessor will draw up a report of needs, including specialist requirements such as needing a ventilator to help with breathing. These "assessed needs" will form the basis of the care and funding.
It's a good idea for a family member or friend to be present for the assessment.
To have your care assessed you'll need:
Visit Which? Elderly Care for more information on how to prepare for the needs assessment.
Once you've established care needs, you're in a position to discuss whether you're eligible for financial support.
If you're looking to get domiciliary care, the situation is rather complicated...unhelpfully, the point at which financial help kicks in is different for every single local authority. Some will pay to put rails up, some won't. Some will fund a special bath, others won't. This is the notorious postcode lottery in care which the government has pledged to reform - but for the time being, your eligibility for financial help will be determined as much by what the local authority has a policy of paying for as by your need.
Many local authorities will only fund care for people whose needs are judged to be "severe" (though some will fund "moderate" care needs). Again, the government has pledged to establish a base level of qualifying need across the country but, for the time being, you will have to take into account the local eligibility level.
Even if the person needing care expects to pay, it's a good idea to get a Section 47 assessment, in case they later run out of money. It's useful to understand how their needs are officially seen - whether severe, moderate or mild.