If no correlation exists between the variables, the points appear randomly scattered on the coordinate plane. If a large correlation exists, the points concentrate near a straight line. Scatter plots are useful data visualization tools for illustrating a trend. If the vertical (or y-axis) variable increases as the horizontal (or x-axis) variable increases, the correlation is positive.
Whiplash Whiplash, a severe neck injury, can cause stiffness and pain in the neck, headache, dizziness, and more. Aortic stenosis Aortic stenosis is a condition of the heart causing shortness of breath, dizziness, or chest pain.
Tension headaches are the most common headache type, representing approximately 60% of all headaches. These headaches are caused by the sustained contraction of the muscles in the neck and head region. The sustained muscle contraction is usually a result of a combination of the following: 1  cervical/neck misalignments and faulty neck biomechanics. 2  previous neck/upper back injury- not properly rehabilitated. 3  poor posture. 4  excessive emotional stress. 5  anxiety or depression. 6  prolonged sitting or driving. 7  improper sleeping habits.