Your description is too sketchy to present any theory as to what could possibly have caused brown marks on your face. There are many kinds of marks that can occur on the face, and there could also be many reasons these marks could come about. Since you have not described the frequency, type, color or size of these marks, there could be any number of reasons they have come about. Sometimes, we can develop acne that leaves behind brown marks on the face. If this was the problem you faced, you should be aware of it as well. Acne marks can be lightened considerably by making it a regular habit to apply aloe vera gel to them. It is also possible that you may be suffering from a bout of pigmentation that is leading to the formation of these marks. If this is the case, then you need to seek medical advice, and that too from a dermatologist. Only this kind of a doctor can make an accurate diagnosis about exactly what you are suffering from and what needs to be done about it as well. In some cases, it could also be a slew of hormonal changes that have left behind these marks. If this is the case, you need not worry too much. They will take care of themselves eventually. Hormonal changes can actually leave marks all over the body. These marks also look extremely dangerous and usually appear to be very stubborn. But once your hormonal imbalance is corrected and your hormonal balance has returned to normal, these will gradually fade away. However if this is the case, then you need to be told this by a doctor only. If you are female and pregnant, keep in mind that this could also be a cause of these marks appearing.
The crux of the matter is that if you have been suffering from these discolored pigmentations for a long time, you should get them closely examined by a doctor. Only then will you be able to take proper care of them and get rid of them properly and accurately. In particular, if the marks are on your face, then you should not really wait too long. This will merely make the situation worse. Also, if they become too deep set, chances are that you may not be able to get rid of them altogether. So it is better to avoid taking a risk by delaying.
answered by G R