Mats should be removed to prevent them growing. The grow because they catch up more and more hair which can lead to your cat’s skin being pinched resulting in pain and discomfort.
I think you have to be sensible and decide whether it is possible to remove mats at home. It depends on how bad they are. You can do harm to a cat if you try and remove them when you’re not really up to the task. You shouldn’t be too ambitious or overoptimistic. A good dose of common sense is required. It may look easier than it is. There is potential for harm which needs to be recognised. You can’t just dive in and brush away heavily and vigourously or pull a comb through your cat’s hair with force. That is simply not how it’s done because you will harm your cat.
On the basis that the mats aren’t that bad and you feel that you are dexterous and careful enough to do the job then you should read on. There are two tools that you can use which may help. One is a commercial tangle remover liquid or spray which may soften the mass and facilitate its removal. These liquids penetrate the tangled hair which helps to release the hair from the knot which helps to remove it through brushing/combing.
Further, on Amazon you can buy special combing tools designed to remove mats. I’ve used neither of these products so I can’t endorse them. However, if you do use them I think it goes without saying that you should be careful. In fact carefulness is critical if you are carrying out a home treatment of this type. Care and gentleness are the guiding principles.
Some mats can be removed with the tip of a comb and sometimes you have to remove them by cutting them out. You can cut out mats with scissors but it must be done with extreme care. The great difficulty here is that you really can’t cut them out out by placing the scissors horizontally to the skin at the base of the fur. This is because you are very likely to cut the skin. This must be avoided at all costs because you would be making the matter worse and causing your cat even more distress.
Rather than sliding the scissors beneath the mat and cutting horizontally it is suggested that when possible you should slide a comb beneath the mat and above the skin to act as a barrier to protect the skin. You then hold the scissors perpendicular to the comb i.e. at 90° to the comb and snip into the furball in narrow strips. This breaks up the mat and allows you to tease out he remaining tangles gently with your fingers. Once the bulk of the mat has been removed this way you can then comb out the rest gently.
Cats with badly matted coats need to be taken to a veterinarian where they will sedate the cat and remove the mats with a professional, powered trimming device such as they use at a professional groomer.
As for groomers, I would avoid them. As far as I know they are not registered or regulated in most or in all countries (or US states) and therefore you don’t know how good they are. You don’t know whether they will do their job sensitively with respect for the cat and without causing any pain. There have been some unpleasant stories of cats being harmed and even killed at grooming parlours. I would trust in your veterinarian.
In warm weather, some cat owners like to give their long-haired cats a lion cut or simply trim the hair to prevent mats forming and to allow the cat to feel less hot. I don’t think that this is cruel although the cat may be put under a general anaesthetic which is dangerous. In which case the potential downside or risk might outweigh the benefits which makes the idea debatable at least.
I have personal experience of using a professional groomer to remove mats from a cat I own some years ago. The mats were not bad but I thought they were too difficult to safely remove myself. My cat returned without the mats but I felt sure that she had been traumatised judging by her behaviour on her return. I felt that she had been abused. I could be wrong but that was my opinion at the time. It’s a reason why I would not recommend groomers.
I have to mention the obvious namely prevention is better than cure. When I took my cat to have her mats removed I was a failure. I had let my cat’s fur become matted. It could have been prevented. If you comb your cat’s fur regularly, say once a day or once every other day, the fur should not become matted. Arguably, every cat should be flea combed daily anyway so why not combine the two tasks? A domestic cat’s matted coat is a failure in cat caretaking. That sounds harsh but ultimately it is true.