Pain in the low back can be a result of conditions affecting the bony lumbar spine, discs between the vertebrae, ligaments around the spine and discs, spinal cord and nerves, muscles of the low back, internal organs of the pelvis and abdomen, and the skin covering the lumbar area.
Chronic sinusitis Chronic sinusitis, or sinus infections, cause a stuffy or runny nose, tooth pain, fever, sore throat and more. Mononucleosis Mononucleosis is a viral infection causing extreme fatigue, sore throat, fever, rash, muscle aches, and more.
As for a red face, this can have a wide variety of causes including rosacea (a skin condition that may also cause swelling and sores), allergies, inflammatory conditions, fever, and sunburn. Medications (including some used to lower blood pressure) can also cause a red face as a side effect. However, one thing that's very unlikely to be behind your red face is high blood pressure. So that's one less thing to get hot and bothered about.