Ignition is usually the easiest of the three to check because on most engines, all you have to do is pull off a plug wire and check for spark when the engine is cranked. On coil-over-plug DIS systems, there are no plug wires so you have to remove a coil and use a plug wire or adapter to check for a spark.
Stress can affect every part of your body. muscle aches, head aches, how your hair grows, the texture of your skin, it can affect your menstrual cycle.
Physical changes. When you are stressed, your body produces more of the so-called 'fight or flight' chemicals which prepare your body for an emergency. Adrenaline and noradrenaline raise your blood pressure, increase your heart rate and increase the rate at which you perspire.