This year influenza is bad. My key test in influenza is not a chest x-ray. It is taking a resting pulse and a walking pulse.
Why? Influenza can cause walking pneumonia. Walking pneumonia is where the lungs are infected throughout and there is tissue swelling. It is different from a lobar pneumonia. In lobar pneumonia people run a higher fever, look sicker, and on the chest x-ray, that part of the lung is white: infection, not air.
In walking pneumonia, the chest x-ray may be read as normal. This is because all the lung tissue is equally swollen. The swelling means that there is less air space. The person may feel ok at rest. They feel exhausted when they walk because the heart must take up the slack for the missing air space, the swollen lungs. At rest this week one person's heart rate is 84. After walking it is 124. Normal is 60-100, so 124 is like running a marathon: exhausting and hard on your heart and body.
I have patients saying "I was sick two weeks ago and I am still exhausted." If their pulse is much over 100 after they walk, they cannot work until it comes down. If they work and wear themselves out, the lungs can't heal. The treatment is rest. If they are at work with a pulse of 114 or 124, then they risk getting a secondary infection in already damaged lungs. They could die.
Check your pulse at home. Count the number of heartbeats in 60 seconds. That is your pulse. Walk around, sit down, and check again. That is the walking pulse. Over 100 is not normal.
This is a bad influenza. The tamiflu (oseltamivir) helps but works best in the first three days of flu. Check your pulse, be seen, rest and get well.