Figures of speech based on real feelings? What causes the physical symptoms?

What are some figures of speech based on real feelings? I thought of three: blood boiling, lump in my throat and heartache.

When you say, "My blood is boiling" you don't actually feel bubbling in the veins but you feel a hot flush, your muscles tighten and constrict, heart pounds. This one is easy to explain - I think the rush of anger raises the blood pressure and temperature too, thus the feeling your blood is boiling.

We've all had a lump in our throat when we encounter something sad, touching or heartbreaking. It's hard to swallow - why?

When you say, "My heart aches" sometimes that is true. A deep profound sadness does seem to cause a heavy ache in the breastbone. Every breath seems heavier, your chest can even physically ache where your heart is. Sometimes it feels like it swells up in your chest. It must be some sort of response from the body to emotion, but what are the physiogical explanation for this very real feeling of heartache?