Some natural remedies for thick toenails caused by fungus include diluted tea tree oil, coconut oil and baking soda mixed with vinegar, according to Everyday Roots. Prevent nail fungus from reoccurring by keeping feet clean and dry.
Nail fungal infections begin as white or yellow spots, advises Everyday Roots. As the infection progresses, the toenail thickens and may change color.
Tea tree oil is a natural disinfectant with antibacterial and fungicidal properties, explains Everyday Roots. Soaking in baking soda and vinegar is effective for treating the fungus that causes thickened toenails because the acidity of vinegar kills fungus while baking soda prevents it from spreading. The fatty acids in coconut oil kill fungus by disrupting its cell membranes.