It's certainly possible to be stressed without saying anything or even without knowing it yourself, so your question is a good one. The outward signs of stress vary from one person to another, but typical signs include losing your temper more easily than usual or getting upset over smaller things.

Some people may turn in on themselves in times of stress, avoiding contact and discussion with others. It's said that this is more common in men than women. Others try to deal with stress by working very hard and never taking a break, or drinking or smoking heavily to try and calm themselves, so it also depends on the person's character.

Stress often causes some health problems like headaches or insomnia, so if your husband seems generally unwell or is sleeping badly that could be another sign. You can find a list of common stress symptoms and causes here.