Your cat has a hard time telling you when she's ill. Here are some of the major cat illness symptom categories and how to spot problems.

Cats are very good at hiding discomfort and signs of illness, but sometimes this comes out as a change in behavior. If you notice a change in your cat's typical routine, you'll want to check for a physical problem.

Defecation and urination -- A number of cat health issues present as urination and defecation issues.

FLUTD (feline lower urinary tract disease) is a group of problems and can involve stones, crystals, infection, or inflammation. Some of these urinary tract problems can be life threatening.

Excessive urination can be a sign of cat illness such as feline diabetes. Excessive licking in the groin or anal area can be a sign of problems.

Occasional constipation is common in cats, and is most often caused by hairballs. Treatments are available for this, and include store bought hairball remedies as well as veterinarian prescribed treatments such as lactulose.

Constipation over the long term may lead to a serious bowel condition known as megacolon. Impacted anal glands may present and will require treatment.

If your cat is howling or crying out while using the litter box, or makes frequent but unsuccessful trips to the box, she may have some physical problem that needs to be looked at. Also, a common sign of trouble is scooting across the floor while dragging the rear end.

If you notice that your cat is not using the litter box, always assume a physical cause may be at fault. If your cat is not urinating or defecating or is missing the litter box, contact your veterinarian.

Diarrhea may indicate intestinal disease and can lead to dehydration, which can be fatal. Other things to look for are evidence of blood in urine or feces, including black tarry stools.

Eye and mouth problems -- The haw, or nictating membrane, is a "third eyelid" that you will sometimes see when a cat's eyes are open. This is often an indication of illness. Check your cat's eyes for cloudiness, pupils of uneven size, or discharge.

Pallor of the lips and gums is a sign of disease and could indicate anemia. Other possible cat illness symptoms include bad breath, ulcers in the mouth, and obviously, loose teeth.

Skin and hair issues -- The skin and coat of your cat can be used as a measure of overall health. Poor coat or problem skin can be a sure sign of cat illness.

A poor or oily looking coat is a sign of illness. If you notice that cat has stopped grooming, it's a sure sign of a problem.

Also look for swelling, hair loss, excessive dryness or flaking, or skin eruption or growths. Check your cat at least once per week for parasites.

These are a few of the major categories of cat health problems. Keeping alert to your cat's routine, and being sensitive to any of the possible above problems is an essential part of cat care.