There are several indicators that may suggest the presence of a fungal infection in your toenails. If your nails are thick, discoloured (yellow-brown), brittle, ragged, distorted in shape, or emit an unpleasant odor, it may be a sign of a fungal infection. While these symptoms can occur individually or in combination, they can also resemble symptoms of fingernail infections. It is important to note that self-medicating or using skincare products to treat infected nails is not advisable, and you should consult with a doctor before attempting any such treatments.