Yes
Depends which psychiatric illness...
A symptom is a characteristic of illness, to which the antonym would be normality.
A person who assumes the worst about a mild symptom may be exhibiting health anxiety or hypochondria. This can manifest as frequent worry or distress about having a serious illness despite reassurance from medical professionals. It can lead to excessive health-related behaviors and frequent seeking of medical help.
Diabetes can be a dormant illness, meaning it often does not show symtoms until later down the road, or they can be very subtle. One symptom of is a highly unquenchable thirst and frequent urination.
Hepatitis A
Yes
Anything can be a symptom of something, contact a doctor if you're seriously concerned about it.
Frequent urination can be a symptom of some STDs in females, but it is not a common symptom across all STDs. It is important to get tested and seek medical advice if experiencing frequent urination or any other unusual symptoms.
Not eating is a symptom of mental illness. It can also be a symptom of other medical problems. Since it is a symptom, it is extremely difficult to determine if it is a cause.
No, may be an Weak stomach or "the runs"
I would say its a symptom of something. You should get an appointment with the vet.
Cachexia