Hi MrsStan
Welcome to the forum, you might want to have a look at the following FAQ which explains where everything is
Welcome to Benefits and Work If you report a Change then you should do so in writing as the date of your letter will be used to set the start date of any new award, Ideally, send it using a Track'd post so that you have proof of delivery.
Before you report a Change you should be certain that you would reasonably qualify for a higher award, not all deterioration or even new conditions will result in your scoring the points you need for a higher award. See our PIP Claims guide for the criteria that you will need to make.
If you report a Change then you will be sent a new PIP2 to complete and it is almost certain that you will be required to have some sort of assessment, your evidence will need to be very clear and compelling for a Paper Based Review to be done.
Gary