The law in England and Wales recommends that anyone who is elderly or seriously ill should ask a medical practitioner, such as a GP, to act as a witness to their will. This is particularly important if you are mentally ill or have a terminal illness, as you need to be able to demonstrate testamentary capacity when writing a will.
If you feel like this might apply to you, you could ask your GP or specialist to witness your will. But remember, you’ll still need a second person to witness your will, and they both need to watch you sign it at the same time.