Common barriers to effective communication include:
Stress and out-of-control emotion. When you're stressed or emotionally overwhelmed, you're more likely to misread other people, send confusing or off-putting nonverbal signals, and lapse into unhealthy knee-jerk patterns of behavior. To avoid conflict and misunderstandings, you can learn how to quickly calm down before continuing a conversation.
Lack of focus. You can't communicate effectively when you're multitasking. If you're checking your phone, planning what you're going to say next, or daydreaming you're almost certain to miss nonverbal cues in the conversation. To communicate effectively, you need to avoid distractions and stay focused.
Inconsistent body language. Nonverbal communication should reinforce what is being said, not contradict it. If you say one thing, but your body language says something else, your listener will likely feel you're being dishonest. For example, you can't say "yes" while shaking your head no.
Negative body language. If you disagree with or dislike what's being said, you may use negative body language to rebuff the other person's message, such as crossing your arms, avoiding eye contact, or tapping your feet. You don't have to agree, or even like what's being said, but to communicate effectively and not make the other person defensive, it's important to avoid sending negative signals.