Cats groom for hours a day, so a little loose fur on the sofa is nothing to think twice about. A bald patch is a different matter. Whether it is a thin strip along the belly, a raw spot behind an ear, or fur that just seems to be disappearing from one area, real hair loss almost always has a cause worth finding, rather than something to wait out. The pattern of the hair loss, and what is happening to the skin underneath it, usually points straight at the answer.
Start by looking closely at the patch
Before anything else, part the fur around the bald area and actually look at the skin, because what you see there narrows the possibilities fast. Smooth, healthy-looking skin under a clean bald patch, especially one your cat can reach easily with its tongue, points toward overgrooming. Red, scabby, flaky, or broken skin points toward an itch-driven cause like fleas or allergy. A circular, crusty patch with a slightly raised edge is the classic look of ringworm, which is a fungal infection rather than anything to do with grooming habits at all. Where the hair loss sits on the body matters too: belly and inner-thigh bald strips are the classic overgrooming pattern, while patches around the neck, base of the tail, or spread across the back more often mean fleas or allergy.
Fleas are the most common cause by far
Even indoor cats get fleas, carried in on clothing, other pets, or a visitor, and flea-bite irritation is the single most common reason a cat scratches and licks itself bald. Cats are also fastidious self-groomers, so a genuinely flea-ridden cat can groom away most of the visible fleas and leave you finding only the evidence, tiny black flea dirt in the fur, and the fur loss, rather than the fleas themselves. Run a fine-toothed flea comb through the coat near the tail base and lower back, then tap any dark specks onto a damp paper towel. Flea dirt dissolves into a reddish-brown smear, since it is really digested blood, which is the easiest way to confirm fleas without ever seeing one alive.
Allergy and overgrooming from stress
Once fleas are ruled out, the two next most likely causes are a skin allergy and stress-driven overgrooming, and they can look surprisingly similar from a distance. A food or environmental allergy, to a protein in the diet, pollen, dust mites, or a cleaning product, tends to cause genuine itchiness, so you will usually see scratching, redness, and broken or chewed-looking fur rather than a neat bald strip. Stress-driven overgrooming is different: it is a licking behaviour, often on the belly, inner legs, or flanks, done as a self-soothing habit rather than because of an itch, and it often leaves oddly smooth, symmetrical bald patches with no redness at all underneath. Our guide on the signs of a stressed cat covers the other changes that tend to show up alongside it, hiding more, changes in appetite, toileting outside the tray, which help confirm stress as the driver rather than a coincidence. A cat that overgrooms heavily can also end up swallowing more hair than usual, so a sudden increase in hairballs alongside thinning fur is worth noticing too.
Less common causes worth knowing about
Ringworm, despite the name, is a fungal skin infection rather than a worm, and it causes a distinctive circular, crusty, hairless patch that can spread between pets and to people in the household, particularly children. It needs a vet diagnosis and proper antifungal treatment rather than home management. Hormonal conditions like an overactive thyroid can also cause coat changes in older cats, usually alongside weight loss and increased appetite, and a nutritional gap in a poor-quality or unbalanced diet can leave a coat generally thin and dull rather than bald in one obvious patch. Both are less common than fleas or stress but worth mentioning to your vet if the more obvious causes do not fit.
When to see a vet
See a vet for any bald patch with red, scabbed, or broken skin underneath, any ring-shaped or crusty lesion, hair loss spreading across multiple areas, or hair loss alongside weight change, increased thirst, or appetite change. Book a routine check too for a smooth, stress-pattern bald patch that does not improve within a couple of weeks of reducing an obvious stressor, since a vet can rule out a physical cause and, if needed, point you toward a feline behaviourist. Cats are not supposed to go bald in patches, so while the cause is often straightforward to treat once found, “wait and see” is rarely the right first move.
Common questions
- Why does my cat have a bald patch?
- The most common causes are fleas, a skin allergy, overgrooming brought on by stress, or occasionally ringworm, a mineral deficiency, or a hormonal condition. Fleas and allergies usually cause the most visible itching and scratching, while stress-driven overgrooming often happens with no obvious itch at all, just a cat licking a spot bald.
- How can I tell if my cat is losing fur from stress or from a skin problem?
- Stress-related overgrooming tends to leave a smooth, symmetrical bald strip, often along the belly or inner legs, in a cat you can actually catch licking, with no scabs or redness underneath. A skin problem like fleas, allergy, or ringworm usually comes with redness, scabs, broken hair rather than a clean bald patch, or a ring-shaped lesion, and often visible discomfort. When in doubt, a vet visit tells the two apart quickly.
- Is cat hair loss always a sign of a serious problem?
- No, fleas and mild stress-related overgrooming are both common and both very treatable once identified. That said, hair loss is rarely nothing, since healthy cats do not usually go bald in patches, so it is always worth working out the cause rather than waiting to see if it resolves on its own.
- Can I catch ringworm from my cat?
- Yes, ringworm is a fungal infection that can spread between cats and people, particularly children, and it typically causes a circular, crusty, hairless patch rather than a smooth bald spot. If you notice a ring-shaped lesion on your cat, or a new itchy rash on your own skin, see a vet and doctor rather than waiting.
