The US national debt has surpassed 34 trillion USD, becoming a major concern for the global economy. The main causes are high public spending, tax cuts, and low borrowing interest rates over a long period. The increasing debt puts pressure on the budget, interest rates, and market confidence. In the long term, if not controlled, public debt could weaken the USD, cause financial crises, and hinder growth. The US Congress needs to find a solution to balance revenue and expenditure to avoid the risks of bad debt and stabilize the economy.