Physiological barriers to communication can occur due to physical health conditions of the sender or receiver that impact communication. Physical defects like stammering, poor eyesight, or illnesses can disrupt communication if any body organs necessary for communication are not functioning properly. Psychological barriers are caused by human psychological problems and operate at the emotional level. Emotions like fear, anger, and worry can block the mind and blur thinking, preventing messages from being organized and conveyed effectively. Status differences and differences in individual perceptions due to unique emotional makeup, knowledge, experiences, and mindsets can also distort communication.