I concur with tschock, but I would suggest obtaining tea tree oil, the 100% oil type in a bottle with a dropper or brush. Apply it to all 10 nails every day after showering. You can also use neem soap and soak in apple cider vinegar now and then to assist in clearing it but the tea tree oil cleared my nails. Yes, you have to continue it for 3-6 months, but it works. Carefully trim any loose nail portions off as they grow, including any spots with nail separation. Cutting off the loose nail and then doing the oil is key to curing this.
It's either fungus or psoriasis. You should see a doctor for some prescription ointment.