tenzija

1. (between people, countries) tension
   Tenzije između dve zemlje rastu. — Tensions between the two countries are growing.
   Na sastanku se osećala tenzija. — You could feel the tension at the meeting.
2. (inner state) tension; stress
   Posle ispita je sva tenzija nestala. — After the exam, all the tension was gone.
3. colloq. (of health) blood pressure
   Lekar mi je izmerio tenziju. — The doctor took my blood pressure.
   Skočila mu je tenzija od nervoze. — His blood pressure shot up from nerves.

About relations it is often used in the plural: tenzije.