1 No early symptoms. 2  Blood in the urine - often intermittently. 3  Kidney area lump. 4  Abdominal swelling.  No pain - there is not usually any kidney pain unless the tumor is very advanced.
Gas content varies depending on what sort of material melted to form the magma. As a general rule, the most explosive eruptions come from magmas that have high gas levels and high viscosity, while the most subdued eruptions come from magmas with low gas levels and low viscosity.
The most powerful eruptions are called plinian and involve the explosive ejection of relatively viscous lava. Large plinian eruptions--such as during 18 May 1980 at Mount St. Helens or, more recently, during 15 June 1991 at Pinatubo in the Philippines--can send ash and volcanic gas tens of miles into the air. The resulting ash fallout can affect large areas hundreds of miles downwind.