Communicating well is one thing.  Communication when under a lot of stress is quite another. Scientists explain that biology can take over in situations like this - our innate fight or flight response kicks in. Adrenaline levels heighten, you start to sweat and your heart beats faster. All of this creates a type of inner noise, causing difficulties in focusing and expressing yourself clearly, as you feel vulnerable and a bit targeted.

If you are starting to feel this way during a conversation, you need to begin with some groundwork even before you speak. Getting a handle on those physical reactions will prepare you far better than any words, grounding you and making it less likely that you’ll respond in an emotionally explosive way. 

Think about what you are doing, and how your body is responding. Slow your breaths and be conscious of the air coming in and out. This will help to calm down your heart beats, and remind your brain that you are not under attack, turning you away from your anxiety and into a more calm space.

Be aware of where your shoulders are! We can often hold a lot of tension there and raise them while also clenching our jaw. Realise that this is happening - lower your shoulders and relax your muscles. 

Grounding yourself can also help - notice your feet, plant them squarely on the ground, be aware of the earth beneath you, how you are stable and planted. This little technique can again pull you away from your anxieties and remind you that you are safe and secure. 

If you are able to, it can also help to clench and release muscles (preferably ones that aren’t overly visible to the other person!) as this forces those muscles to relax, rather than stay in fight or flight mode. 

If you are mid-conversation and notice that it is getting a bit fraught, check that your stance and body language is neutral and non-threatening. Are your fists clenched, arms and legs crossed? This is a closed body position and sends unspoken messages that you aren’t for compromising and will not accept the other person’s viewpoint. 

Keep a relaxed eye gaze - not staring the other person down, nor flitting everywhere except their face.  Both can make for increased nervousness. Also, keep a respectful distance and that neutral stance mentioned above. Leaning in can be an act of aggression, unless you are mirroring the other person. 

Copying someone else’s movements is called ‘mirroring’. This can happen unconsciously in everyday interactions, for example, smiling when someone else smiles, nodding in agreement while they also nod.  We can also choose to mirror their actions consciously as an act of rapport - this triggers ’mirror neurons’ and lowers that sense of conflict.

Listen better, and reflect back what you’ve heard. Discuss any disparity and clarify the facts. The other person will feel more heard and understood, and misunderstandings through heated emotions will be reduced. Don’t interrupt.
Only when you are finished reflecting back and you are sure you understand the other person THEN put your view forward.  Speak simply and clearly - this is the most effective way during a stressful situation.

Ultimately consider why you are both communicating. Healthy communication is constructive - you both want to achieve an outcome that works for both of you. Don’t offer advice or lectures - truly listen to each other. The best solutions come when we work them out ourselves, not through being told what to do. Keep you eye on your own goals, while being open and allowing the other person to reach theirs. Of course, this might mean compromise from both people.  You both matter.