If code runs indefinitely, it's usually due to an infinite loop caused by incorrect loop conditions or missing termination criteria. Reviewing all loops and ensuring conditions update correctly at each iteration is essential. Common culprits include while loops with improper exit conditions, or for loops where counters don't increment or reset as expected. Adding debug points, like printing variable states inside loops, can help trace where a loop might be failing to exit. Recursive functions without proper base cases can also cause indefinite execution by continually calling themselves. Identifying the condition that prevents a loop or function from ending allows for a fix, ensuring the code executes within the expected time limits.