actually rare to find nematodes hookworms in the LUNGS temselves but rather the larvae which invade the lung tissue via pulmonary vessels coughed up in mucus, swallowed then grow to adults in small intestine. In Heavy infestations they will also be seen in the colon and cause hemo/cardio abnormality like tachycardia, pallor, anemia and heartfailure.
Ascarid, also are RARELY if ever found in lungs, as they tend to feed on fecal matter, but again, the larval stage passed through the lungs (termed "Loefflers syndrome" and may be coughed up in sputum. Ascarid is an easy ID as it looks like a large white earthworm that usually hangs out in the GI tract unless chased out by meds/herbs (potentially life threatening). These are more likely to be vomited/choked up rather than cough due to the size, but can also be seen crawling out the nose, again trying to escape from meds or anesthesia. http://en.wikipedia.org/wiki/Ascaris
Fluke however can be found in various tissues, such as the paragonimis typically in the lungs but also organs including brain, heart etc. Burning sensation more typically associated with flukes, either allergy to VERY toxic byproducts (sometimes lethal), inflammation of 100,000's of migrating larvae or histamine reaction to antigenic material released by dying parasites. Alot of these symptoms overlap making it extremely difficult to diagnose empirically.
Breathing issues can occur due to larval migration through the lungs by nems or trems or presence of adult flukes causing inflam reaction, not to mention, again, an asthma/allergic reaction of lung tissue to parasite by products which also creates a higher sensitivity of the lungs to air conditions. SOB can occur due to heavy parasite burden such as flukes or hookworms that stress the circulatory system and decrease the oxygen exchange efficiency of the lung tissue. So you cant assume if you are SOB you have ascarid "breeding" in the lungs (almost impossible) or that if you cough up string looking mucus that its worms when its more likely larvae. Even eggs coughed up will be typically ONLY paragonimis or rarely strongyloid, both of which are MICROSCOPIC. Massive larval migration through lungs may also cause bacterial pneumo.
Headaches can occur (usually)with larval migation of most species which can be found in the vessels, brain tissue, ventricles or spinal collums and occasionally flukes and rarely strongyloides. Folks ifyou had ACSARID munchin on your brain you wouldnt be chatting about it, but on the floor convulsing. H/A can also occur from the toxic by products of parasites and again the strain they put on the cardiovascular system that causes vessels to dilate (thats why caffeine aleviates b/c it vasoconstricts. Massive larva migration can cause also meningismus (tight neck) and even changes in vision (floaters), hearing (ringing or pain) and memory as will parasite death which can also cause massive brain swelling (enceph) potentially fatal.