Blisters, hot spots and black toenails: find the cause, then the fix

What to fix first

Before you buy anything, check the free fixes. Most repeat blisters trace back to lacing or fit, not to a missing product. A heel that lifts and drops with every step, laces tight enough to cut circulation but loose enough to let the foot slide, or a boot that's slightly the wrong width for your foot will out-blister any sock you put inside it. Start with how to prevent blisters hiking, which walks through the full fix order, and hiking boot lacing techniques if you haven't tried a heel-lock lace pattern yet. Both cost nothing and take a few minutes at the trailhead.

How the fixes divide

Once fit and lacing are handled, the rest of this hub splits into three practical categories. Socks and liners come first, because they're cheap, you already wear one, and swapping cotton for a merino or synthetic blend is the single biggest change most hikers can make. We cover full-cushion crew socks in best hiking socks for blisters and toe-specific socks and liners, for blisters between the toes specifically, in best toe and liner socks. Tape and padding come next, for a spot you already know is a repeat offender: see Leukotape vs moleskin for how a rigid strapping tape compares to soft cut-to-size padding. Break-in and footwear questions come last, covering how long a new boot should take to stop rubbing, how much heel slip is normal, and why toes take a beating on steep downhills.

What decides which sock or tape you actually need

The deciding factor is location, not brand. A blister on the back of the heel is almost always a lacing or fit problem first and a sock problem second. A blister between the toes is a skin-on-skin friction problem that a five-toe sock addresses more directly than a thicker crew sock does. A blister on the ball of the foot often points to a worn insole or a lot of steep downhill mileage rather than the sock at all. Cushion level matters too: more padding underfoot can mean a snugger fit through the toe box, so a thicker sock isn't automatically the safer choice. None of this is a spending decision. It's a diagnosis, and the right fix is usually the cheapest one that matches the actual cause.

The common mistake

The most common mistake here is buying a fix before diagnosing the cause: a new pair of socks for a heel that's actually slipping because of loose lacing, or a thicker insole for a toe box that's actually too narrow. The second most common mistake is ignoring a hot spot because stopping to fix it feels like it will cost you trail time. It doesn't. A spot you tape or re-lace around in under a minute is a non-event; the same spot ignored for another hour is usually an open blister by the time you make camp. If a blister does form, keep the skin over it intact where you can and cover it rather than draining it yourself. That specific guidance, and when it's worth seeing a clinician instead, is covered in how to prevent blisters hiking.