Fascia can be tight because of injury, overwork, sedentary, unhealthy diet, lifestyle, monotonous work, etc. The fluid part in the fascia gets more viscous and the flow gets slower, the collagen fibers will be more tight and the cells will produce more collagen to strengthen the fascia and it will be more stiff. There are a lot of nerve receptors which can signaling pain in the fascia. If the fascia gets stiff, the receptors may be subjected to a higher pressure and hence, they signal more pain