OP you missed this section from the NHS definition.
Health anxiety
Health anxiety is when you spend so much time worrying you're ill, or about getting ill, that it starts to take over your life.
But this is probably the one you need to take a look at:
What is germaphobia?
Germaphobia (also sometimes spelled germophobia) is the fear of germs. In this case, “germs” refers broadly to any microorganism that causes disease — for instance, bacteria, viruses, or parasites.
Symptoms of germaphobia
We all have fears, but phobias tend to be viewed as unreasonable or excessive compared to standard fears.
The distress and anxiety caused by a germ phobia are out of proportion to the damage that germs are likely to cause. Someone who has germaphobia might go to extreme lengths to avoid contamination.
The symptoms of germaphobia are the same as the symptoms of other specific phobias. In this case, they apply to thoughts and situations that involve germs.
The emotional and psychological symptoms of germaphobia include:
intense terror or fear of germs
anxiety, worries, or nervousness related to exposure to germs
thoughts of germ exposure resulting in an illnesses or other negative consequence
thoughts of being overcome with fear in situations when germs are present
trying to distract yourself from thoughts about germs or situations that involve germs
feeling powerless to control a fear of germs that you recognize as unreasonable or extreme
The behavioral symptoms of germaphobia include:
avoiding or leaving situations perceived to result in germ exposure
spending an excessive amount of time thinking about, preparing for, or putting off situations that might involve germs
seeking help to cope with the fear or situations that cause fear
difficulty functioning at home, work, or school because of fear of germs (for example, the need to excessively wash your hands may limit your productivity in places where you perceive there to be many germs)