A toxic friendship is one that consistently leaves you feeling worse, drained, put down, anxious, or small, rather than supported. Signs include a friend who mocks you often, competes with everything you do, disappears when you need them but expects you to always show up, pressures you, or makes you doubt yourself. One bad day does not make someone toxic, but a steady pattern does.
The first step is to notice the pattern honestly instead of making excuses for it, because we often defend people we care about long after they have stopped treating us well. Once you see it clearly, try setting boundaries. That can mean spending less time with them, not sharing things they twist against you, and calmly speaking up when they cross a line. Sometimes a good friend having a rough phase responds well to an honest conversation and things improve.
But if the pattern continues no matter what, it is okay to step back or let the friendship fade. Distancing yourself from someone who repeatedly harms your wellbeing is not being a bad person, it is protecting your own health, and you are allowed to do that. Growing apart from people is a normal part of life, especially as you change and figure out who you are. Keep your energy for friends who respect you, and do not feel guilty for choosing peace. The right people make you feel more like yourself, not less.
Example: If a friend regularly belittles your goals and you feel worse after every meeting, that is a pattern worth addressing, and if it does not change, worth stepping back from.
One practical tip: Notice how you feel after spending time with someone. Consistently drained is data. Trust it over the label of best friend.