This letter analyzes the effects of inter-carrier interference (ICI) and inter-block interference (IBI) on uplink reception of small cells (SCs) in orthogonal frequency division multiple access heterogeneous cellular networks. Tight upper and lower bounds of the power of ICI and IBI plus co-channel interference from nearby SCs, average rate, and symbol error rate (SER) per SC subcarrier are derived. Results show that the theoretical analysis is close to simulation. Importantly, the average rate and SER are seriously degraded by the interference at high signal-to-noise ratio.